Thank you! That single integer "1099" clarified the whole thing for me! Of bloody course Coinbase is providing a service just like, say, Schwab does for stock accounts. And part of that service ought to be a nice, neat, verifiable year-end statement, "trading through us this year, you made/lost $X in taxable capital gains."

My 1099s from several Schwab accounts are the basis for much of my tax return each year and I am quite grateful for the way Schwab abstracts so much complicated accounting into a single statement that both I and the IRS can trust without question.

Is there a BTC exchange that DOES provide 1099-type statements?