Goldman Sachs CEO Lloyd Blankfein is weighing in on the biggest debate raging on Wall Street: the prospect for the burgeoning market for digital currencies.

In a tweet, the prominent Wall Street executive and former trader appeared to signal that the jury is still out on bitcoin, but also cautioned skeptics to consider that the rise of paper money over gold might also have fostered similar doubts from market stalwarts.

Here’s the substance of his tweet: “Still thinking about #Bitcoin. No conclusion-not endorsing/rejecting. know that folks also were skeptical when paper money displaced gold.”

Blankfein’s comments on Twitter are in contrast with more decidedly critical remarks from banking peer Jamie Dimon, J.P. Morgan Chase & Co.’s JPM, -0.21% boss, who compared bitcoin’s parabolic gains over the past year with the 17th-century mania for tulip bulbs, which eventually imploded. Dimon referred to bitcoin as a “fraud” and said it “won’t end well.”

The slightly more subdued remarks from Blankfein also follow reports that indicate that the world’s most prominent investment bank wants to take advantage of the boomlet in cryptocurrencies, and is weighing a new trading operation dedicated to that sector.

In recent trade, a single bitcoin was down 2.3% at $4,300, but it is up about 350% so far in 2017. Comparatively, the S&P 500 index SPX, -1.11% is up more than 13% year to date and the Dow Jones Industrial Average DJIA, -0.87% has gained about 15%, while the Nasdaq Composite Index COMP, -1.07% has risen 21% over the same period.

The rapid ascent of cryptocurrencies has made it impossible for Wall Street investors to ignore digital assets that didn’t exist less than a decade ago. Bets on its success, or failure, have been ramping up with each all-time high.

Read: Opinion: Stay away from bitcoin and ethereum — they are complete garbage

Wall Street experts, including BlackRock boss Larry Fink and Morgan Stanley CEO James Gorman, among many others, have weighed in on bitcoin over the past few weeks.

That’s not likely to change until the debate is settled.