That'd be right clicking to snatch the chart URL, which contains the stock symbol and date parameters. Peeking into the future would certainly help one's rate of return a bit :)

Yes, I thought of this but didn't think someone would go to the trouble to look at the stock and date, then look up the price N-days after that, then go back and trade it. Apparently I was wrong! I could solve this by dynamically creating an image w/ PHP and trimming the stock & date, but my poor shared CPU wouldn't like that...

Just store their current stock symbol & dates as session variables, and make the src of the image be a .php file which has the one liner:

<?php header("Location: http://quote-web.aol.com/..."); ?>

Then you don't have to use image processing (including actually reading the image), and they'd have to become right-click-and-copy-paste-image-src-check-in-new-tab-cheater! :-)

Why not throw a div over the image or... disable right click, make a little harder to cheat... at least.