Discipline is the key to successful trading. Long ago, when I was a clerk on the trading floor, I was considering what to do with my life: Do I continue on and try and carve out a career as a trader? Or do I leave my job as a clerk and try something else?

I started doing some practical research. I asked some floor traders I know what it takes to make it as a trader. I'll never forget the response of one trader. It's stuck with me throughout my career. He said, "To be a successful trader, you have to be good at losing money".

This, of course, seemed like some pretty counterintuitive advice. Losing money? I don't want to lose money! I want to make it! But any experienced trader knows that along with winners come losers. Throughout a long career, you'll have thousands of both. The real key to being successful isn't having all winners, it's managing your losers.

Some conventional trading wisdom is "take your losses early, and let your profits run". This trading idiom is easy to memorize, easy to intellectualize, but sometimes hard to follow. Stubbornness can get in the way. Along with left-brain mathematics and right-brain creativity, human psychology is a huge factor in trading success. Understanding how the market thinks is one thing, but understanding yourself and controlling your emotions with steadfast discipline, is the key to longevity as a trader.

** On Wednesday, October 19 at 6:00 p.m. EDT, TheStreet's Options Profits is hosting a webinar featuring Fred Ruffy of WhatsTrading.com. Join Fred as he outlines how to look at the "big picture", drill down into the sectors and ultimately find the individual options trade. Utilizing specific trade examples and case studies, Fred will show you how to select simple and advanced options plays. The back half of the webinar will include an interactive, exciting Q&A session.

Please email: jill.malandrino@thestreet.com to secure a slot for the webinar as space is limited and for the link to the presentation. If you have already RSVPd, DO NOT send another one. A spot has been reserved for you.

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