I just took on a new client who was a high-frequency trader last year.  He has a 1099-B with proceeds and cost of roughly $1.5B (net gain of around $100k).

I put in all of the sales (the ones with wash-adjustments, anyway) but the 1099-B worksheet, and Schedule D itself, are limiting the totals to $999,999,999 with a red error message that it cannot display anything larger.  

If it was just the 1099-B worksheet I could break it up into multiple submissions, but I'm not sure how to handle Schedule D - I can't create a second Sch D that totals the correct amounts.  Do I fudge the proceed/cost amounts to ensure the net gain matches? (and attach a statement explaining it)?  Any other suggestions?