in late december you decide, for tax purposes, to sell a losing position that you hold in twitter, which is listed on the nyse, so that you can capture the loss and use it to offset some capital gains, thus reducing your taxes for the current year. however, since you still believe that twitter is a good long-term investment, you wish to buy back your position in february the following year. to get this done you call your charles schwab brokerage account manager and request that he immediately sell your 1 comma 400 shares of twitter and then in early february buy them back. charles schwab charges a commission of $4.95 for online stock trades and for broker-assisted trades there is an additional $25 service charge, so the total commission is $