Bug: batch_get_prices passes no date range — silently returns ~20 rows instead of years of history

[bradsmithmba]

Summary

YFinanceProvider.batch_get_prices calls self.get_price_history(symbol) with no start, end, or period arguments. yfinance defaults to 1 month of daily data (~20 rows). Feature calculators that require 252+ rows (ADX, Bollinger, _rolling_rank with window=252) receive an undersized frame and produce mostly-NaN features. No warning or error is raised.

Evidence

src/data/providers.py lines 132-139:

def batch_get_prices(self, symbols):
    for symbol in symbols:
        results[symbol] = self.get_price_history(symbol)  # no period/start/end

get_price_history signature: (symbol, start=None, end=None, interval="1d"). Default yfinance period when all are None: 1 month.

Fix

Pass a default period covering at least 2 years: self.get_price_history(symbol, start=two_years_ago), or add a days parameter to batch_get_prices that mirrors the single-fetch API.