Nasdaq 100's unrelenting declines ring a dot-com bust alarm bell

The Nasdaq 100 tumbled 7.5% this week as what started as an aggressive selloff in speculative corners spread to the rest of the market.

Bulls should be glad there were only four days this week instead of five.

To wit, the Nasdaq 100 just did something it hasn’t done since the aftermath of the internet bubble: fall more than 1% in every session of a week. It doesn’t count as a superlative because Monday was a holiday. But for investors caught up in the selloff, it felt like something shifted.

A full week of big down days hasn’t happened since the dot-com bubble burst, first in April 2000 and then in September 2001. Back then, the Nasdaq went on to fall another 28% before