As tech giant Nvidia soars on hype around artificial intelligence, and global stock indexes notch record highs, debate has grown about whether the stock market has entered a "bubble."
That's generally seen as a period in which asset prices inflate rapidly, potentially beyond their core value — and risk crashing just as fast.
Bob Parker, senior advisor at trade body International Capital Markets Association, told CNBC's "Squawk Box Europe" on Wednesday he saw signs of a bubble based on two of three main characteristics.
If we look at the valuation of Nvidia, justifiably it is actually very high indeed," Parker said, adding that the second sign is investor positioning.
"Whenever you have a market bubble, investors are very clustered or very concentrated, either in one market or in one sector.
Persons:
Bob Parker, CNBC's, Parker, we've
Organizations:
Capital Markets Association, Nvidia
Locations:
Europe