In the past three months, a tremendous amount of healing has taken place. As a nation, we've come together in a way that has surprised even the optimists.

The Taliban lost its grip on Afghanistan; the economy has shown surprising resiliency. The stock market, a sideshow in this drama, has recovered the ground it lost since Sept. 11 and more.

But some stocks have done better than just heal. They've doubled and even tripled from their Sept. 10 closes.

We screened for companies with market capitalizations of more than $1 billion that have gained more than 100% since Sept. 10. We came up with 13 of them. All trade on the

Nasdaq

and all are tech-related, for starters.

Notably, very few of them are up for a readily discernible reason.

Polycom

(PLCM)

, for example, is up on the notion that video and audio conferencing is going to continue to be a popular option for flight-wary companies and still-displaced financial district firms. The stock jumped more than 30% when trading resumed the Monday after the attacks and hasn't looked back.

But for most of the companies -- particularly those furthest from their 52-week highs -- it's harder to find fundamental reasons for the climb.

Ariba

(ARBA)

, for example, is up 207% since Sept. 10. Since then it has replaced its CEO, made some more job cuts and said good things at its analyst meeting. All of those things are nice, but they hardly explain a tripling in price. Hang it on animal spirits.