All trades imported from supported brokers/platforms after April 2, 2012 have commission and fee data included where available. Note this is the date imported - not the date of the trades.
If you have trades that you imported before that date, they will be missing the commission/fee data. It is possible to overlay the data on top of the data in the Tradervue, without causing any issues.
It is strongly recommended that you only try this by using the same data files you initially imported. Also, if you are using the Lightspeed bookmarklet, that will NOT work for this update process; you will need to copy/paste the data, save to a file, or use the automated importer.
To overlay commission data, click this import link. You will see a warning about being in commission-overlay mode. In this mode, no new trades will be created; your existing Tradervue data will be updated with the commission/fee data. When the process is complete, you will see a message about duplicate trades being detected and nothing was imported; this is expected. If you then check your trades, you should see the updated data.
Please contact us if you have any questions about this process.
Note that commissions and related items (e.g. reporting net P&L data) require a gold subscription.