As Nicolas had only bought a few shares and had set a stop-loss as well, so even though he went wrong in these trades, he did not incur too many losses. And the other two trades that proved right, Nicolas increased his investment in those two shares. It means he invested more in the trades where he was successful and cut his losses short in trades where he went wrong. The two trades Zenith Radio and Fairchild Camera where he was successful, he increased his investments there and thus made huge profits here.