I've seen similar questions regarding ttax limit, which I believe is 2000 transactions.
I have 16720 transactions and here is the work-around.
Log-in to Schwab, go to History, Realized Gain
Select previous year.
If you hit the Schwab limit (10000 I think),
then ask for Jan1 to June30, July1- etc
Once you have all the data downloaded as .CSV files,
you can merge them together and upload into Google Sheets.
Total the columns and verify the results with Schwabs PDF statement.
Now you can modify (squash) the lines into whatever you want.
If all you have is Wash Sales adjustment, skip the downloads.
Just read the Schwab PDF last page totals.
In TTax: Import (once) the schwab info. (Int, Div, Trades, DepositInfo)
You'll get Int, Div, DepositInfo imported and a message tooManyTrades
TTax Forms select SchedB adjustments...
the form explains "Entering greater than $9,999,999.00 values".
Enter your Schwab PDF values and W code.
This same metho should work for TaxAct and other software too.
It worked for my 16,752 transactions and $476,000,000.00+ values
