Is it incorrect for my 1099-B to be showing a few lines with a cost basis of $0?. I am fairly sure this is due to option spreads, so trying to make sure I report properly

[wilsonmazimba11]

Given these are spreads, I imagine I can go through line by line and calculate the cost basis for each spread, but wanted to check and see if it's expected that way in some cases.

[JohnB5677]

It is possible, but I suggest you check each posting.  If you sold an option short, and it expired, the zero cost basis would be correct.

However, from time to time the broker does not know what the cost basis actually was.  In that case you would be incorrectly taxed on the full amount of the proceeds.

If you do have transactions that do require a cost basis, this tool may help.

You may be able to use Historical Stock Quote Prices - MarketWatch to determine the original value.

[wilsonmazimba11]

Ah, that makes sense. Thank you for the response on this! This is super helpful. 

I'll just review each transaction and double check to calculate the appropriate cost basis. 

Thanks,

Will