"Some say if everyone is talking about a bubble, it’s a sign there isn’t one. Yet bubble arguments raged in 1999 even as it continued to inflate. The same is happening now.
One big difference between now and 1999-2000 is the scale of price gains. Sure, Nvidia’s up a lot (really, a lot). But gains in the company’s shares of 54% this year to an October peak, and 30% including the drop since then, pale in comparison to the leaps in 1999.
Cisco more than doubled in a month from mid-October 1999, while Apple was up 150% that year and Intel gained 75% in just under three months early in 2000.
Even the best big stocks this year, names such as Western Digital, Seagate and Micron Technology, only tripled or quadrupled to their peaks this week, before falling hard on Friday. In 1999, Qualcomm soared 2,620%. It took until 2020 before it recovered from the subsequent bust.
Ultimately, whether this is a bubble depends on whether it pops. If it turns out AI can’t deliver both the promised productivity gains and fat profits for its creators, the parallel will be to the painful dot-com aftermath, not the boom."