Commissions not deductible?

I took a look at page 67 of the IRS Pub 550 (http://www.irs.gov/pub/irs-pdf/p550.pdf) which explains the specifics of trader status. Under expenses, it says that commissions are not a deductible expense. Is this is true? It seems like such a huge cost of doing business to a trader to not be deductible.

 

i believe u add that on to cost basis of the stock when u buy/sell

 

Commissions are included in your cost basis as a calculation of profit and loss.

 

thanks!