Quant Mashup - Tradevo DataEmail summaries are back. Get the Quant Mashup delivered to your inbox every 1-3 days. Never more than one email per day. No spam and no sharing your address. Look for the email link in the header and sidebar. - Mike Lookahead Bias in Fundamental Backtests: 66 Days, Measured [Tradevo Data]If your backtest joins fundamentals on the fiscal-period-end date, it is trading on numbers that did not exist yet. That's the whole bug, in one sentence. A company's fiscal year ends, and then — weeks later — a 10-K gets filed and the numbers become public. Join on the wrong date and(...)