Add dataset card

README.md

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+---
+license: mit
+task_categories:
+  - time-series-forecasting
+language:
+  - en
+tags:
+  - crypto
+  - finance
+  - 1s-klines
+  - binance
+pretty_name: 1-Second Crypto OHLCV Data (Binance)
+size_categories:
+  - 1B<n<10B
+---
+
+# 1-Second Crypto OHLCV Data (Binance)
+
+Historical 1-second kline (candlestick) data for 6 major cryptocurrencies
+downloaded from [Binance Vision](https://data.binance.vision/).
+
+## Assets
+
+| Symbol   | Start      | End        |
+|----------|------------|------------|
+| BTCUSDT  | 2019-01    | 2026-03    |
+| ETHUSDT  | 2019-01    | 2026-03    |
+| BNBUSDT  | 2019-01    | 2026-03    |
+| XRPUSDT  | 2019-01    | 2026-03    |
+| DOGEUSDT | 2019-07    | 2026-03    |
+| SOLUSDT  | 2020-10    | 2026-03    |
+
+## Schema
+
+| Column       | Type    | Description                      |
+|--------------|---------|----------------------------------|
+| open_time_s  | int64   | Unix timestamp in **seconds**    |
+| open         | float64 | 1-second open price              |
+| high         | float64 | 1-second high price              |
+| low          | float64 | 1-second low price               |
+| close        | float64 | 1-second close price             |
+| volume       | float64 | Base asset volume                |
+
+## File Structure
+
+```
+data/{SYMBOL}/{SYMBOL}_{YEAR}.parquet
+```
+
+Each file is one calendar year for one asset, Snappy-compressed Parquet.
+
+## Usage
+
+```python
+import pandas as pd
+
+# Load one asset, one year
+df = pd.read_parquet(
+    "hf://datasets/commanderzee/1s-crypto-data/data/BTCUSDT/BTCUSDT_2024.parquet"
+)
+
+# Load all years for one asset
+from datasets import load_dataset
+ds = load_dataset("commanderzee/1s-crypto-data", data_files="data/BTCUSDT/*.parquet")
+```
+
+## Source
+
+All data sourced from [Binance Vision](https://data.binance.vision/) public archives.
+Timestamps normalised to Unix seconds (integer division of raw ms/μs timestamps).