There's a lot of Bitcoin holders lining up to cash in on the huge gains BTC saw last month.

That kind of selling pressure could cause some turbulence in markets, according to BRN analyst Valentin Fournier.

"The Bitcoin spot sell wall currently exceeds 4,000 BTC and shows no signs of diminishing, as Bitcoin's price remains relatively stagnant this week," he wrote in a note shared with Decrypt. "This sell wall serves as a key indicator of the selling pressure that needs to be overcome for Bitcoin to break through the six-figure mark."

At the time of writing, Bitcoin's price has managed to climb back above $96,000 after earlier seeing a slide from $97,000, according to CoinGecko data. In the past day, traders have shifted about $85 billion worth of BTC.

The price has climbed a staggering 40% compared to this time last month, according to CoinGecko. But

Crypto analytics platform IntotheBlock also noted that Bitcoin exchange flows have started to paint a picture of investors getting ready to cash in. The flow of BTC on and off trading platforms used to show a net outflow, the company noted, but on Tuesday alone users transferred $230 million worth of BTC into exchange wallets.

But even if there are signs of impending volatility, that hasn't stopped the wider crypto market from benefiting—and it hasn't scared off large-scale investors.

"As Bitcoin and Ethereum continue to build strong support at these elevated levels, the broader crypto market is expanding, led by the impressive performance of altcoins," Fournier said. "We anticipate that Bitcoin will benefit from sustained institutional inflows and could attempt a breakout in the coming week."

Sure enough, altcoins like Tron and XRP have been posting huge gains, with Tron hitting an all-time high price Tuesday and the Ripple-linked XRP jumping to a seven-year high on Monday.

And despite indications of impending sell pressure in spot markets, institutional interest in spot Bitcoin ETFs has remained strong. Just yesterday, Bitcoin ETFs added $676 million and are inching closer to drawing even with the stash of BTC held in wallets belonging to Bitcoin's pseudonymous creator Satoshi Nakamoto.

Edited by Andrew Hayward