Investors have long memories.

In 2000, after a bubble that saw the Nasdaq (^IXIC) gain nearly 500% in seven years, tech stocks crashed.

The Nasdaq lost almost 80% from peak-to-trough and in recent years, the market rally and particularly the run-up we’ve seen in tech stocks has had many asking if we’re in for a repeat of that painful crash.

On Wednesday, the S&P 500 (^GSPC) information technology sector, made a new record high for the first time since March 2000. Year-to-date, the Nasdaq is up over 18%. In early afternoon trading on Thursday, the tech-heavy index was again leading the market and on track to log a tenth straight day of gains.

The standout stocks have been the now ubiquitous FANG stocks — Facebook (FB), Amazon (AMZN), Netflix (NFLX), and Google-parent company Alphabet (GOOGL). Year to date, each of these stocks is up better than 25%, with Netflix and Facebook rising more than 40% in 2017 alone. (On Tuesday, Netflix gained 13% after an earnings beat, sending shares to a new record high.)

Analysts at Goldman Sachs earlier this year slightly re-framed the group as FAAMG, adding Apple (AAPL) and Microsoft (MSFT). Also feel free to add an N — shares of chipmaker Nvidia (NVDA) are up 56% this year and the stock’s gains since the start of 2016 now total 407%.

Together, the FAAMG stocks have a market cap of nearly $3 trillion. In a note earlier this year, UBS strategist Julian Emanuel pointed out that through early June these stocks had accounted for one third of the S&P 500’s year-to-date gains, not an unusual state of affairs.

But as research has shown, most of the market’s total return is always driven by just a few constituents. This is also why low-cost indexing is the best way for individual investors to bet on the stock market: the chances you pick a losing stock far exceed the chances you pick a winner.

So is it time to be worried about tech stocks?

As Yahoo Finance editor-in-chief Andy Serwer said Thursday, the only thing to be worried about is that tech stocks (as measured by the S&P 500 IT sector) are up 23% year and much more when looking at the aforementioned FAANNMG stocks. (FAANNMG doesn’t have quite the same ring to it, in fairness.) And anything that goes up that much in a short period is vulnerable to a price adjustment in the short run.

But unlike the pre-tech crash bubble, the tech sector as a whole has strong earnings growth.

In a report earlier this month, analysts at BlackRock (BLK) highlighted the following chart showing that tech earnings have risen in-line with the index’s price.

“The technology sector has been a standout performer in 2017,” the firm wrote.