The reason is detailed in the article. Fed increased rates in a very short amount of time and people fled the stock market for the safer interest rates...
"At the same time, a decline in interest rates increased the availability of capital.[20] The Taxpayer Relief Act of 1997, which lowered the top marginal capital gains tax in the United States, also made people more willing to make more speculative investments."
...
"Meanwhile, Alan Greenspan, then Chair of the Federal Reserve, raised interest rates several times; these actions were believed by many[weasel words] to have caused the bursting of the dot-com bubble."
"At the same time, a decline in interest rates increased the availability of capital.[20] The Taxpayer Relief Act of 1997, which lowered the top marginal capital gains tax in the United States, also made people more willing to make more speculative investments." ... "Meanwhile, Alan Greenspan, then Chair of the Federal Reserve, raised interest rates several times; these actions were believed by many[weasel words] to have caused the bursting of the dot-com bubble."