The tech breakout is suspect: Facebook, Amazon, Google, Apple rule

Pisani's market open: Weird tech activity

There's something strange going on in Tech Land.

On Friday, the hit a historic high and the made multi-year highs, but breadth was negative with three stocks declining for every two advancing.

Huh? Historic highs for the Nasdaq, but more stocks declining than advancing?

That is a weird divergence, and there's a reason for it.

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The leadership is very narrow. A small group of tech stocks are pushing the indices higher. And that is worrisome.

If you are a broad investor—I mean the kind that invests in the S&P 500—it's no secret that there are three sectors that matter: technology, financials, and health care.

But technology really matters. It's 20 percent of the market cap of the S&P 500, the largest sector.

Right now, there are four technology stocks that really matter.