"""Step 1: Collect the small-cap ticker universe. Universe definition: union of small-cap-and-below tickers from major S&P/Russell/iShares ETFs: - IWM: iShares Russell 2000 ETF (Russell 2000 small-caps) - IJR: iShares Core S&P SmallCap ETF (S&P 600 small-caps) - IWC: iShares Micro-Cap ETF (micro-caps below small-cap threshold) Tickers exceeding the S&P 600 upper bound ($7.4B median market cap) are filtered out downstream in preprocess.py via SMALL_CAP_MAX_MEDIAN_MCAP. We do NOT filter on ETF holding value here because it does not correlate with actual company market cap (mega-caps may have small ETF positions). This satisfies Prof. Hwang's Requirement 1.1: "Collect R2K + small caps". - Uses iShares CSV data directly for market value, sector, exchange. - Normalises multi-class share tickers (e.g. BFA -> BF-A) so yfinance can find them. - Removes duplicates, zero-price entries, and non-equity rows. Output: data/universe/benchmark_universe.csv """ from __future__ import annotations import io import logging import math import os import tempfile import time import httpx import pandas as pd from . import config logger = logging.getLogger(__name__) _MAX_HTTP_RETRIES = 3 # Sanity bounds for company market cap (USD). # Anything outside this range is treated as an invalid lookup. _MCAP_MIN_VALID = 1.0e5 # $100k — below this is almost certainly bad data _MCAP_MAX_VALID = 1.0e13 # $10T — above this is impossible # yfinance lookup pacing — pure serial. # # Empirically, ANY parallelism (even 4 workers × 0.3s delay = ~5 req/s) # triggers Yahoo's per-IP rate limit on runs of >2000 tickers, dropping # coverage to ~60%. Pure serial at ~3 req/s stays under the threshold and # achieves ~99% coverage. For ~5,345 tickers this takes ~27 minutes — that # is the minimum reliable wall time for this dataset size. _MCAP_LOOKUP_DELAY_SEC = 0.3 # iShares strips the dash from multi-class share tickers. # This map restores the yfinance-compatible format. _CLASS_SHARE_FIXES: dict[str, str] = { "BFA": "BF-A", "BFB": "BF-B", "BRKB": "BRK-B", "LENB": "LEN-B", "MOGA": "MOG-A", "MOGB": "MOG-B", "GEFB": "GEF-B", "CWENA": "CWEN-A", "UHALB": "UHAL-B", "CRDA": "CRD-A", # Crawford & Co Class A — non-voting "CRDB": "CRD-B", # Crawford & Co Class B — voting } # NASDAQ Trader public symbol directory — authoritative source for ALL # US-listed common equities (NASDAQ + NYSE + NYSE Mkt + AMEX). Used to # populate Prof. Hwang's third universe component: small caps that are # NOT in any major index (recent IPOs, between-rebalance additions, # dropped-from-index small caps still trading). _NASDAQ_LISTED_URL = "https://www.nasdaqtrader.com/dynamic/symdir/nasdaqlisted.txt" _OTHER_LISTED_URL = "https://www.nasdaqtrader.com/dynamic/symdir/otherlisted.txt" def _download_ishares_holdings(url: str) -> pd.DataFrame: """Download iShares ETF holdings CSV and return a cleaned DataFrame.""" for attempt in range(_MAX_HTTP_RETRIES): try: resp = httpx.get(url, follow_redirects=True, timeout=60) resp.raise_for_status() break except Exception as exc: if attempt < _MAX_HTTP_RETRIES - 1: wait = 2 ** attempt * 5 logger.warning("iShares download failed (attempt %d/%d), retrying in %ds: %s", attempt + 1, _MAX_HTTP_RETRIES, wait, exc) time.sleep(wait) else: raise text = resp.text # iShares CSVs have metadata rows before the actual header. lines = text.splitlines() header_idx = 0 for i, line in enumerate(lines): if line.strip().lower().startswith("ticker"): header_idx = i break csv_text = "\n".join(lines[header_idx:]) df = pd.read_csv(io.StringIO(csv_text)) df.columns = [c.strip() for c in df.columns] if "Ticker" in df.columns: df = df[df["Ticker"].notna() & (df["Ticker"].str.strip() != "-") & (df["Ticker"].str.strip() != "")] df["Ticker"] = df["Ticker"].str.strip().str.upper() # Filter out junk rows (e.g. iShares copyright disclaimers parsed as tickers) df = df[df["Ticker"].str.len() <= 10] # Keep only equity instruments (remove futures, cash, CVRs, etc.) if "Asset Class" in df.columns: before = len(df) df = df[df["Asset Class"].str.strip().str.lower() == "equity"] dropped = before - len(df) if dropped > 0: logger.info("Filtered %d non-equity entries (kept %d equities).", dropped, len(df)) # Remove zero-price entries (CVRs, escrows, delisted, private vestings # that iShares mislabels as Equity) if "Price" in df.columns: price_num = pd.to_numeric(df["Price"].astype(str).str.replace(",", ""), errors="coerce") before = len(df) df = df[price_num > 0] dropped = before - len(df) if dropped > 0: logger.info("Filtered %d zero-price entries (CVRs/escrows/delisted).", dropped) return df def _download_nasdaq_trader(url: str) -> pd.DataFrame: """Download a pipe-delimited NASDAQ Trader symbol directory file. Both nasdaqlisted.txt and otherlisted.txt share the same format: pipe-delimited, one header row, last line is a 'File Creation Time' footer that must be skipped. """ for attempt in range(_MAX_HTTP_RETRIES): try: resp = httpx.get(url, follow_redirects=True, timeout=60) resp.raise_for_status() break except Exception as exc: if attempt < _MAX_HTTP_RETRIES - 1: wait = 2 ** attempt * 5 logger.warning("NASDAQ Trader download failed (attempt %d/%d), retrying in %ds: %s", attempt + 1, _MAX_HTTP_RETRIES, wait, exc) time.sleep(wait) else: raise text = resp.text # Drop the trailing "File Creation Time" footer line lines = [ln for ln in text.splitlines() if ln and not ln.startswith("File Creation Time")] df = pd.read_csv(io.StringIO("\n".join(lines)), sep="|") df.columns = [c.strip() for c in df.columns] return df def _collect_uncovered_smallcaps(already_seen: set[str]) -> list[dict]: """Return candidate records for Prof. Hwang's third universe component: small caps listed on NYSE/NASDAQ that are NOT in any major index (specifically not in the IWM/IJR/IWC ETF holdings already collected). Each record is a dict with keys: ticker, exchange, name. The exchange and security name come directly from the NASDAQ Trader symbol directory files (no extra API calls). Sector is filled later by collect_fundamentals. The mcap filter (≤ $7.4B) is applied later in run() via the same serial yfinance lookup pass; this function only produces the candidate set. Filtering rules: - Drop ETFs (ETF=Y in nasdaqlisted.txt) - Drop test issues (Test Issue=Y) - Drop tickers already in IWM/IJR/IWC (passed via `already_seen`) - Drop preferreds (containing '$' or '.' which mark preferred classes) - Drop warrants and units (suffix W/U/R on a 5-char base) - Keep only common stock (Common Stock / Common Shares in security name) """ logger.info("Downloading NASDAQ Trader symbol directories ...") nas = _download_nasdaq_trader(_NASDAQ_LISTED_URL) oth = _download_nasdaq_trader(_OTHER_LISTED_URL) logger.info("nasdaqlisted: %d rows, otherlisted: %d rows", len(nas), len(oth)) candidates: list[tuple[str, str, str]] = [] # (ticker, exchange_code, security_name) # ── nasdaqlisted.txt fields: Symbol|Security Name|Market Category|Test Issue|Financial Status|Round Lot Size|ETF|NextShares if not nas.empty: nas = nas[nas["Test Issue"].astype(str).str.upper() != "Y"] nas = nas[nas["ETF"].astype(str).str.upper() != "Y"] for _, row in nas.iterrows(): sym = str(row.get("Symbol", "")).strip().upper() sec_name = str(row.get("Security Name", "")) if not sym or sym == "NAN": continue candidates.append((sym, "NASDAQ", sec_name)) # ── otherlisted.txt fields: ACT Symbol|Security Name|Exchange|CQS Symbol|ETF|Round Lot Size|Test Issue|NASDAQ Symbol # Exchange codes: A=NYSE Mkt (AMEX), N=NYSE, P=NYSE Arca, Z=BATS, V=IEX if not oth.empty: oth = oth[oth["Test Issue"].astype(str).str.upper() != "Y"] oth = oth[oth["ETF"].astype(str).str.upper() != "Y"] # Keep only NYSE-family exchanges oth = oth[oth["Exchange"].astype(str).str.upper().isin(["N", "A"])] for _, row in oth.iterrows(): sym = str(row.get("ACT Symbol", "")).strip().upper() sec_name = str(row.get("Security Name", "")) exch = "NYSE" if row.get("Exchange") == "N" else "NYSE_MKT" if not sym or sym == "NAN": continue candidates.append((sym, exch, sec_name)) # Filter to common stock only (drop preferreds, warrants, units, notes, # rights, depositary shares, etc.). Use security name keyword whitelist # — most US-listed equities have "Common Stock" or "Common Shares". common_kws = ("common stock", "common share", "ordinary share", "class a common", "class b common", "class c common") drop_kws = ("preferred", "warrant", "unit ", " unit", "% notes", "depositary", "right ", " rights", "subordinate", "convertible", "trust preferred", "% senior", "debenture", " etn ", "exchange-traded note") # Build per-ticker dict (dedupe by ticker, prefer first occurrence) by_ticker: dict[str, dict] = {} for sym, exch, sec_name in candidates: sn_low = sec_name.lower() if any(k in sn_low for k in drop_kws): continue if not any(k in sn_low for k in common_kws): continue # Drop ticker symbols that look like preferred/warrant variants: # tickers containing $ or . (preferred class markers like BAC.PA), # 5-char tickers ending in W (warrant), U (unit), R (rights). if "$" in sym or "." in sym: continue if len(sym) >= 5 and sym.endswith(("W", "U", "R")): continue if sym in by_ticker: continue # first occurrence wins # Strip the " - Common Stock" suffix from the security name for cleaner display clean_name = sec_name for suffix in (" - Common Stock", " - Common Shares", " - Class A Common Stock", " - Class B Common Stock", " - Class C Common Stock"): if clean_name.endswith(suffix): clean_name = clean_name[: -len(suffix)] break by_ticker[sym] = { "ticker": sym, "exchange": exch, "name": clean_name.strip(), } # Subtract already-known tickers (those in IWM/IJR/IWC) new_records = [r for sym, r in sorted(by_ticker.items()) if sym not in already_seen] overlap = sum(1 for sym in by_ticker if sym in already_seen) logger.info("NASDAQ Trader common-stock candidates: %d (after subtracting " "%d already-known tickers: %d)", len(by_ticker), overlap, len(new_records)) return new_records def _fetch_one_market_cap(ticker: str) -> float | None: """Fetch a single ticker's company market cap from yfinance. Uses ONLY `fast_info.market_cap` — a single fast network call. The deliberately simple approach avoids the multi-fallback hangs that occur when `tk.info` blocks for 30+ seconds on rate limits or bad tickers. Tickers where fast_info fails are returned as None and dropped from the universe per Option A (a small-cap benchmark cannot include a ticker without a verified market cap). Returns a float USD value in [_MCAP_MIN_VALID, _MCAP_MAX_VALID] or None on any failure. """ import yfinance as yf # local import — yfinance is heavy try: mc = yf.Ticker(ticker).fast_info.market_cap except Exception: return None try: mcf = float(mc) except (TypeError, ValueError): return None if not math.isfinite(mcf): return None if not (_MCAP_MIN_VALID <= mcf <= _MCAP_MAX_VALID): return None return mcf def _serial_fetch_pass(tickers: list[str], pass_label: str) -> dict[str, float | None]: """One serial pass over `tickers`. fast_info call + delay per ticker.""" results: dict[str, float | None] = {} total = len(tickers) if total == 0: return results logger.info("%s: %d tickers, serial, %.2fs delay ...", pass_label, total, _MCAP_LOOKUP_DELAY_SEC) t0 = time.time() for i, t in enumerate(tickers, start=1): results[t] = _fetch_one_market_cap(t) time.sleep(_MCAP_LOOKUP_DELAY_SEC) if i % 200 == 0 or i == total: elapsed = time.time() - t0 ok = sum(1 for v in results.values() if v is not None) rate = i / elapsed if elapsed > 0 else 0 eta = (total - i) / rate if rate > 0 else 0 logger.info(" %s progress: %d/%d (ok=%d) — %.0fs elapsed, ETA %.0fs", pass_label, i, total, ok, elapsed, eta) return results def _fetch_market_caps(tickers: list[str]) -> dict[str, float | None]: """Fetch market caps via two serial passes for maximum coverage. Pass 1: serial fast_info call for every ticker (~3 req/s, no rate limit). Pass 2: serial retry of any tickers that returned None in pass 1 (catches transient errors; permanent no-data tickers will fail again and be dropped per Option A). Pure serial avoids the per-IP rate limit that even 4 workers triggered. Expected wall time for ~5,345 tickers: ~27 min pass 1 + ~3 min pass 2. """ t0 = time.time() # ── Pass 1: serial over all tickers ── results = _serial_fetch_pass(tickers, pass_label="Pass 1") pass1_ok = sum(1 for v in results.values() if v is not None) logger.info("Pass 1 complete: %d/%d resolved in %.0fs", pass1_ok, len(tickers), time.time() - t0) # ── Pass 2: serial retry of pass-1 failures ── failed = [t for t in tickers if results.get(t) is None] if failed: retry_results = _serial_fetch_pass(failed, pass_label="Pass 2 (retry)") recovered = 0 for t, mc in retry_results.items(): if mc is not None: results[t] = mc recovered += 1 logger.info("Pass 2 complete: recovered %d/%d failures", recovered, len(failed)) final_ok = sum(1 for v in results.values() if v is not None) logger.info("Total market_cap coverage: %d/%d (%.1f%%) in %.0fs", final_ok, len(tickers), 100 * final_ok / len(tickers), time.time() - t0) return results def run() -> pd.DataFrame: """Execute Step 1 and return the universe DataFrame.""" config.UNIVERSE_DIR.mkdir(parents=True, exist_ok=True) out_path = config.UNIVERSE_DIR / "benchmark_universe.csv" if out_path.exists(): logger.info("Universe file already exists at %s, loading.", out_path) return pd.read_csv(out_path) def _records_from_ishares(holdings_df: pd.DataFrame, source: str) -> list[dict]: records = [] for _, row in holdings_df.iterrows(): ticker = row["Ticker"] mv_str = str(row.get("Market Value", "")).replace(",", "") try: market_value = float(mv_str) except (ValueError, TypeError): market_value = None records.append({ "ticker": ticker, "market_value": market_value, "sector": row.get("Sector"), "exchange": row.get("Exchange"), "name": row.get("Name"), "source": source, }) return records # ----- Russell 2000 from IWM ----- logger.info("Downloading IWM (Russell 2000) holdings ...") iwm_df = _download_ishares_holdings(config.IWM_HOLDINGS_URL) logger.info("IWM tickers: %d", len(iwm_df)) iwm_records = _records_from_ishares(iwm_df, source="IWM") iwm_set = {r["ticker"] for r in iwm_records} # ----- S&P SmallCap 600 from IJR ----- logger.info("Downloading IJR (S&P SmallCap 600) holdings ...") ijr_df = _download_ishares_holdings(config.IJR_HOLDINGS_URL) logger.info("IJR tickers: %d", len(ijr_df)) ijr_records = _records_from_ishares(ijr_df, source="IJR") # Keep only IJR tickers not already in IWM ijr_only = [r for r in ijr_records if r["ticker"] not in iwm_set] logger.info("IJR-only tickers (not in IWM): %d", len(ijr_only)) # ----- Micro-cap from IWC ----- logger.info("Downloading IWC (Micro-Cap) holdings ...") iwc_df = _download_ishares_holdings(config.IWC_HOLDINGS_URL) iwc_records = _records_from_ishares(iwc_df, source="IWC") seen = iwm_set | {r["ticker"] for r in ijr_only} iwc_only = [r for r in iwc_records if r["ticker"] not in seen] logger.info("IWC-only tickers (not in IWM or IJR): %d", len(iwc_only)) # ----- Uncovered NYSE/NASDAQ small caps (Prof. Hwang component 3) ----- # "those who are not even included in the index (small caps in NYSE or NASDAQ)" # We pull the full NASDAQ Trader symbol directories, filter to common stock # only, subtract everything already in IWM/IJR/IWC, and let the downstream # mcap pass apply the $7.4B small-cap upper bound. The remainder is the # set of small caps that are NOT in any major index (recent IPOs, # between-rebalance additions, dropped-from-index small caps). seen_for_uncovered = iwm_set | {r["ticker"] for r in ijr_only} | {r["ticker"] for r in iwc_only} uncovered_seed = _collect_uncovered_smallcaps(seen_for_uncovered) uncovered_records = [ { "ticker": rec["ticker"], "market_value": None, # iShares-only field; not applicable "sector": None, # filled later by collect_fundamentals "exchange": rec["exchange"], # populated from NASDAQ Trader directory "name": rec["name"], # populated from NASDAQ Trader directory "source": "UNCOVERED", } for rec in uncovered_seed ] logger.info("UNCOVERED small-cap candidates (pre-mcap-filter): %d", len(uncovered_records)) # Build the set of ALL S&P 600 tickers (BEFORE the IJR-only subtraction # against IWM). This is what `in_sp_smallcap_600` should reflect: an # IJR ticker is an S&P 600 small-cap regardless of whether it ALSO # happens to appear in IWM (they overlap by hundreds of names). The # earlier `source` column does NOT capture this -- a ticker in both # IWM and IJR carries source='IWM', losing the SP600 attestation. all_ijr_tickers = {r["ticker"] for r in ijr_records} # Combine: IWM + IJR-only + IWC-only + UNCOVERED all_records = [] for r in iwm_records: all_records.append({ **r, "in_russell_2000": True, "in_sp_smallcap_600": r["ticker"] in all_ijr_tickers, "small_cap_outside": False, }) for r in ijr_only: all_records.append({ **r, "in_russell_2000": False, "in_sp_smallcap_600": True, "small_cap_outside": True, }) for r in iwc_only: all_records.append({ **r, "in_russell_2000": False, "in_sp_smallcap_600": False, "small_cap_outside": True, }) for r in uncovered_records: all_records.append({ **r, "in_russell_2000": False, "in_sp_smallcap_600": False, "small_cap_outside": True, }) df = pd.DataFrame(all_records) logger.info("Combined raw universe: %d tickers (IWM=%d, IJR-only=%d, IWC-only=%d, UNCOVERED=%d)", len(df), len(iwm_records), len(ijr_only), len(iwc_only), len(uncovered_records)) # Normalise multi-class share tickers (iShares strips the dash) fixed = 0 for old, new in _CLASS_SHARE_FIXES.items(): mask = df["ticker"] == old if mask.any(): df.loc[mask, "ticker"] = new fixed += mask.sum() if fixed: logger.info("Normalised %d multi-class share tickers (e.g. BFA -> BF-A).", fixed) # Remove exact duplicates (same ticker appearing as CVR + regular stock) before = len(df) df = df.drop_duplicates(subset="ticker", keep="first") dupes = before - len(df) if dupes: logger.info("Removed %d duplicate tickers.", dupes) # ── Fetch authoritative company market cap from yfinance ────────────── # NOTE: iShares "market_value" is the ETF's holding value, NOT the # company's market cap. We fetch the real market cap here so the saved # universe file is the authoritative small-cap set from the start. # # Every ticker in the saved file MUST have a verified market_cap, or it # is dropped (cannot honestly be classified as small-cap without knowing). tickers = df["ticker"].tolist() mcap_map = _fetch_market_caps(tickers) df["market_cap"] = df["ticker"].map(mcap_map) # Drop tickers with no reliable market cap (delisted, SPAC residue, ADR glitches) invalid_mask = df["market_cap"].isna() invalid_tickers = sorted(df.loc[invalid_mask, "ticker"].tolist()) if invalid_tickers: logger.warning("Dropped %d tickers with no valid market_cap (showing first 30): %s", len(invalid_tickers), invalid_tickers[:30]) df = df.loc[~invalid_mask].copy() # Drop mega-caps from IWC and UNCOVERED sources. # # IWM (Russell 2000) and IJR (S&P SmallCap 600) constituents are # index-designated small-caps by FTSE Russell / S&P Dow Jones methodology # — we respect those classifications and do NOT filter them by current # market cap (a few names may have drifted above $7.4B since the last # index reconstitution, but they remain index-designated small-caps). # # IWC has known mega-cap leakage (iShares holds tiny tracking positions # in NVDA/AAPL/etc. for index-fit reasons) and must be filtered. # # UNCOVERED tickers have no index attestation at all and so require # an explicit small-cap upper bound. The S&P 600 SmallCap upper bound # ($7.4B) is the official threshold per S&P Dow Jones methodology. needs_filter = df["source"].isin(["IWC", "UNCOVERED"]) mega_mask = needs_filter & (df["market_cap"] > config.SMALL_CAP_MAX_MEDIAN_MCAP) mega_rows = df.loc[mega_mask, ["ticker", "source", "market_cap"]].sort_values( "market_cap", ascending=False ) if not mega_rows.empty: logger.warning( "Dropped %d mega-caps from IWC/UNCOVERED (market_cap > $%.1fB). First 30:\n%s", len(mega_rows), config.SMALL_CAP_MAX_MEDIAN_MCAP / 1e9, mega_rows.head(30).to_string(index=False), ) df = df.loc[~mega_mask].copy() logger.info( "Universe after market-cap filtering: %d tickers (max mcap=$%.2fB, median=$%.2fB)", len(df), df["market_cap"].max() / 1e9, df["market_cap"].median() / 1e9, ) # Apply MAX_TICKERS cap if set if config.MAX_TICKERS is not None: df = df.head(config.MAX_TICKERS) # Label lower-end by market value percentile (within Russell 2000 subset) r2k = df[df["in_russell_2000"] & df["market_value"].notna()] if not r2k.empty: threshold = r2k["market_value"].quantile(config.LOWER_END_PERCENTILE / 100.0) df["lower_end_russell2000"] = df["in_russell_2000"] & (df["market_value"] <= threshold) logger.info("Lower-end R2K threshold: market_value <= %.0f (%d tickers)", threshold, df["lower_end_russell2000"].sum()) else: df["lower_end_russell2000"] = False df = df.sort_values("ticker").reset_index(drop=True) # Atomic write: write to temp file first, then rename fd, tmp_path = tempfile.mkstemp(suffix=".csv", dir=out_path.parent) try: os.close(fd) df.to_csv(tmp_path, index=False) os.replace(tmp_path, out_path) except BaseException: try: os.unlink(tmp_path) except OSError: pass raise logger.info("Saved universe (%d tickers) to %s", len(df), out_path) return df