Win rates vary with each trader's trading style and is also subject to market conditions. Therefore, there is no general win rate.
Win rate has virtually no bearing to a traders profits. You can have a high win rate and still lose a lot of $ - you can have a low win rate and make a lot of $. It's all about risk/trade mgmt. Many of the best swing traders on an average year will have about 10% of their trades account for their profits. The other trades of smaller winners and losers will scratch each other out.
Well.... for professionals they have access to flow. And, a lot of banks only flow trade instead of prop. With flow trading it should be around 100% because you're front running customer orders. Seriously, the mutual/pension funds don't care as long as they get filled. So what if you raise the 100,000 share order 50 ticks. It doesn't matter. Inside of bank prop trading it gets more difficult. You've got 20 or so banks colluding to manipulate prices, but you'd be hard pressed to find a job on one of those desks. The win rate is almost 100%, but they do have losses every once in a while. "London whale." At a deposit prop firm, probably 5%-10% (They do have access to RBH, and most who weren't profitable before trading will not go through the hassle to join.) With CPM, closer to 2% As a retail reg-T trader who trades everyday, less than 1% As a buy and hold investor, probably around 60-70% Investing for the long term has, barring a few instances, always worked out for mom and pop.
Well now boys and girls mr Harris has determined and concluded that win rate is a very important metric....so...... http://systemtradersuccess.com/important-performance-measure-trading-strategies/
Its very important to lose many more times than you win. Sounds rather silly doesn't it? Unless you put a premium on being humbled by the markets.
I have seen traders with win rates of 70% and still lose money. I can make money with only 15% win rate. Yes I can have 50 consecutive losses. And I don't use any martingales because it would be so huge.
I always use the venerable late great Jack Hershey, 92% winners, and a 500% yearly profit as a baseline