Get ready for most cryptocurrencies to hit zero.

The tumble in cryptocurrencies that erased nearly $500 billion of market value over the past month could get a lot worse, according to Goldman Sachs Group Inc.’s global head of investment research.

Most digital currencies are unlikely to survive in their current form, and investors should prepare for coins to lose all their value as they’re replaced by future competitors, Goldman’s Steve Strongin said in a report dated 5 February. While he didn’t posit a timeframe for losses in existing coins, he said recent price swings indicated a bubble and that the tendency for different coins to move in lockstep wasn’t rational.

“The high correlation between the different cryptocurrencies worries me,” Strongin said. “Because of the lack of intrinsic value, the currencies that don’t survive will most likely trade to zero.”

Today’s digital coins lack long-term staying power because of slow transaction times, security challenges and high maintenance costs, according to Strongin. He said the introduction of regulated bitcoin futures hasn’t addressed those concerns and he dismissed the idea of a first-mover advantage—noting that few of Internet bubble’s high fliers survived after the late 1990s.

“Are any of today’s cryptocurrencies going to be an Amazon or a Google, or will they end up like many of the now-defunct search engines? Just because we are in a speculative bubble does not mean current prices can’t increase for a handful of survivors,” Strongin said. “At the same time, it probably does mean that most, if not all, will never see their recent peaks again.”

Strongin was more upbeat about the blockchain technology that underlies digital currencies, saying it could help improve financial ledgers. But even there he sounded a note of caution, arguing that current technology doesn’t yet offer the speed required for market transactions.