Friend of Quantopian Jeremiah Lowin recently posted a simple contest on Twitter: Guess a US stock that will be in the top 5 gainers by market cap (measured in absolute dollars) over the coming week.

There's reason to believe that looking at historical data can help us make a better guess at this question. Since the contest is judged in absolute dollar change, it's probably better to pick a large cap stock rather than a small cap stock. A 1% weekly return on a stock with a billion dollar market cap produces a much larger change in absolute market cap than the same return on a stock with a smaller market cap. Also, since we're looking for the stock with the single greatest change, it's probably better to pick a stock with somewhat high volatility. A large cap stock whose market cap changes very slowly is unlikely to be the largest gainer in a single week.

My immediate reaction to the question was "I can use Quantopian to get some empirical evidence for my guess."

This notebook shows how to compute the frequency with which stocks appeared in the top 5 weekly market cap gainers among among all US stocks since April of 2018.

Of course, there's no guarantee that appearing at the top of this ranking means that a stock will top the charts on this particular week, and appearing in this list certainly doesn't mean that you should (or shouldn't) buy one of these stocks; as mentioned above, this is mostly just selecting for large cap high-volatility stocks. But I think this analysis is a nice example of the kind of question that's easy to answer using the tools available on Quantopian.