It was a Dotcom boom, nothing else. I got my USA entry as software dev to work in finance industry for this boom as many others at that era.
Basically someone wrote a software to increase amount of participants in stock game may be thousand fold. The internet happened. The computerization reached the investment game and millions of retiring boomers with money. That is just mass effect. Nothing to do specifically with any tech company. It was as if someone poured a WD-40 on old steam engine and things went crazy. It is force of nature, there is no single individual to attribute the success of what happened in 2000.