The Nvidia (NASDAQ: NVDA) stock performance has been stunning but like every big winner, it leaves regrets in its wake.

While investors who got in early will be thrilled, those who bought it too late, or who never bought at all, may be hurting. You wouldn’t be human if you didn’t feel left out of the fun.

Plus you will be poorer. The Nvidia share price is up a stunning 882% over the last five years. That would have turned a £10,000 investment into a life-enhancing £98,200.

Dare investors buy US tech stocks today?

Some will have given up and be seeking their fun elsewhere. I imagine many are chasing the Micron Technology share price higher. This US semiconductor company is up a staggering 667% in just 12 months. It now regularly features in AJ Bell‘s list of top 10 most bought shares by UK investors. Chip maker Marvell Technology is another popular pretender.

There are plenty more US tech hopes out there, as the artificial intelligence revolution excites and terrifies investors in equal measure. Right now, fear is winning out. At today’s £197, the Nvidia share price has fallen 17% from its all-time high of almost $236, which it hit on 14 May. It’s still up 20% over the last year, but the stellar pace of growth has slowed. Which was inevitable at some point.

In the last week, Micron has fallen around 13% and Marvell by 18%. Their potential may be huge, but anybody who buys these stocks today is entering a world of volatility.

Will the AI bubble burst?

The big concern is that AI is a massive bubble and hyperscalers won’t make a return on the hundreds of billions they’re pouring into developing the infrastructure. But it’s worth pointing out that in contrast to the dotcom boom, these companies are actually making real money, as my table shows.

Net income is the actual amount of money a business has left over after paying all of its expenses, taxes, and interest payments. It’s often called the bottom line.

Micron is now a trillion-dollar company, with Marvell much smaller at $201bn. These three have very different valuations, based on their price-to-earnings (P/E) ratios. Two are dizzying.

• Nvidia – 40x
• Micron – 122x
• Marvell – 172x

Nvidia’s P/E of 40 is pretty high but hardly off the chart given its growth prospects. Q1 revenue jumped 85%. Free cash flow climbed a similar percentage to $48.6bn and is forecast to top $200bn this year. Micron and Marvell are risky given today’s super-sized P/Es.

How much risk can you stand?

Current uncertainty is also driven by fear that the Federal Reserve will start hiking interest rates, to cool the US economy. If it follows through, the tech frenzy would almost certainly cool. Nvidia might retreat further.

The rewards are potentially outsized, but so are the risks. Then again, people have been warning about a tech crash for absolutely years, and the sector keeps powering higher. Ultimately, it’s a personal decision. Can you stand this level of risk? If so, I think it’s worth think about drip-feeding money into Nvidia, taking advantage of any further dips. But I’m treading carefully around Micron and Marvell at today’s valuations.

Should you invest £5,000 in Nvidia right now?

When investing expert Mark Rogers and his team have a stock tip, it can pay to listen. After all, the flagship Twelfth Magpie Share Advisor newsletter he has run for nearly a decade has provided thousands of paying members with top stock recommendations from the UK and US markets.

And right now, Mark thinks there are 6 standout stocks that investors should consider buying. Want to see if Nvidia made the list?

Harvey Jones owns shares in Nvidia.