Calculation of coinbase transactions is wrong. The individual transactions are correct but the proceeds and cost basis are totally wrong. How do I fix this?

[fanfare]

wrong compared to what?

proceeds and cost basis are not calculated.

That is the data that you enter. gain/loss is the calculated value.

@noahliebs 

[noahliebs]

The summary for Coinbase shows 3 things:

1. Total gain or loss 

2. Proceeds

3. Cost basis

This is generated by importing a CSV of transactions. eg: Buy, Sell, Interest, Reward, etc.

The proceeds and cost basis are both in the ballpark of $500k, but i didn't trade an amount anywhere near that. 

I fear that some sort of rounding error / floating point precision botched the calculation

[noahliebs]

Resolved.

Instead of downloading from Coinbase from directly using my credentials I used, "Enter another way" and directly input the gains and losses.

[fanfare]

I see you're saying you imported a large number of transactions, but the subtotal is wrong.

Yes, this can happen due to rounding errors that result from the way TurboTax does rounding.

To be off by $500,000 sounds pretty unlikely but what do I know.
I've never seen a coinbase csv file.

There must be something strange about the data in your csv file.

post a sample line for a couple of transactions.

also post the header line.

@noahliebs 

[noahliebs]

There was nothing strange in the csv; I got it directly from Coinbase.

I narrowed it down to my SHIB transactions.

$500 of SHIB was 12,1 million coins. Before TurboTax compiles the buys and sells into taxable events, the numbers were correct. But as a transaction it basically said i bought $490,000 and sold for the exact same price. 

Sadly, there is no way for me to correct TurboTax's bad math