Wireless Internet and security stocks led internet.com's Internet stock index, the ISDEX, to a 24% gain in April, as an 86% decline in the index proved a little too much for investors to resist.

Not bad for 13 months, an 86% decline. It took the Dow from October 1929 until June 1932 to fall 89%. When it comes to Net stocks, even Depressions happen in Internet time.

Whether April 4 was THE bottom is anyone's guess, but it's worth paying attention to what investors snapped up when they finally put some sidelined cash to work.

Wireless Internet and security stocks dominated the winners list, snagging half of the top ten spaces. The top-performing Net stock in April was GoTo.com, up 141%. The company's pay-per-click search service is suddenly in demand as search and portal sites look for alternatives to advertising.

In second and third place, with gains of 117% and 89%, respectively, were two wireless stocks, InfoSpace and Openwave . Research In Motion came in sixth with a 75% gain. In fourth place was a security stock, Internet Security Systems, with an 87% gain, and Netegrity came in eighth with a 69% run last month.

The only infrastructure stock to crack the top 10 was Juniper Networks , with a gain of 65% in April. Cisco and Sycamore lagged the ISDEX last month, with gains of 13% and 5%, respectively.

Rounding out the top 10 were Sapient (consultants have become takeover targets as of late); Amazon.com , which is remaking itself into a B2B company; and Ticketmaster.

The wireless sector is a promising one for investors looking for long-term opportunities, because the infrastructure for the wireless Web is still in its infancy. Interestingly, it is the number two priority for venture capitalists over the next 12-18 months, right behind next-generation networking equipment. Security and storage are two other areas where earnings have held up relatively well, giving investors hope that demand will be strong in those areas when the economy picks up.

At the bottom of the list for April were many fallen leaders: Scient , Excite@Home, Net2Phone , Red Hat, EarthLink , S1, and Terra Networks , all of which lost from 3% to 10%.

Bear markets can signal a long-term change in market leadership, making sharp rallies like April's worth paying close attention to.