This FAQ
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hasn't changed from last year as far as I can tell. But if you're really doing that many stock trades then you probably should be reporting the bulk of that in a "summary" fashion, sending in hard copy of the detail to the IRS using Form 8453, (or no form at all, depending on what's being reported).
On the page "Tell us about your [Broker name] 1099-B" tick "I'll enter a summary for each sales category". That way you just enter summary figures for proceeds and basis. BE SURE AND CLICK ON AND READ each piece of "On Demand Tax Guidance" you come across (the blue hyperlinks) as you're doing this as TurboTax's interview in this area is pretty weak and you need that "On Demand" guidance to know exactly what to enter and how to enter it as well as how to use Form 8453, if needed.
