How large a position should a trader take? The risk on a single trade should never exceed 1 to 3 percent of the total portfolio size. Thus, at 1 percent, for every $5,000 a trader has in a trading account, he should risk only $50 on each position. For example, a trader with $10,000 in his account can take either two trades where the risk is $50 apiece or one trade in which the risk is $100. Many traders fail at trading because they simply don’t have sufficient capital in their trading accounts to take the positions they want to take.