Since my (outstanding) suggestions didn't get picked (what is up with the Academy ???), the first choice is the best.
On a serious note, it expresses the benefit of the site to a target audience. The others, while good, are too close to trader jargon.
Expanding the phrase to further qualify active traders would be more beneficial. Any person reading the phrase, which may appear on search engine results, etc. would have to be able to discern the exact purpose of the website ...
"The #1 Site For Active Traders" ... active traders of what? Stocks, options, futures, forex, baseball cards, porno? What?
One could expect the audience viewing advertising to be pre-qualified (ad in a financial rag/paper, website, keyword searches), however this is a dangerous assumption. All qualification of the target audience (active traders of the financial markets) should be clearly stated in the website headline ...
The #1 Site For Active Traders Of The Financial Markets
The #1 Site for Active Traders Of Wall Street and Beyond
you get the idea ... ok, time for my medication
