@bbugaski @barflyphoto If you have only one brokerage, you can input summary entries and attach a statement (the details from your brokerage or a spreadsheet). If you have several brokerages, you could repeat the same strategy for each brokerage, which might be clearer than trying to summarize all of them together. Of course, when you file online, the summary probably won't actually be included, but you'll have it in your records, and the amounts will tie out. Ultimately you get in trouble for not paying the right amount of tax, not for how you fill out the forms in good faith!
[I converted the above comment from last year into an answer because it appears there are several people wondering what to do with large numbers of transactions. Typically this situation is probably more likely to apply to people who choose to hire a professional preparer, but times are changing!]
