Less than a week ago, bitcoin’s price set a new all-time high at $19,920.53. However, the oldest cryptocurrency is still struggling to break above the $20,000 level. 

The reason that milestone remains elusive, according to analysts and traders, is simple: There are too many sell orders very near the $20,000 level because some bitcoin holders are afraid of near-term sell-offs. That price point is particularly significant because it’s roughly where the market topped out in the late 2017 rally that saw bitcoin quadruple in price within two months, only to collapse by 70% within the subsequent two months, its biggest (at the time) price correction. 

“A huge [number] of sellers are offering orders near the $20,000 level, which has no doubt created a strong resistance level,” Simon Chen, executive director of investment and trading at Hong Kong-based crypto lender Babel Finance, said. “People are trying to sell at this level based on what happened during the 2017 bull market.”

For some, similarities to 2017 are hard to ignore, particularly the speed by which bitcoin made new record prices. 

The $20,000 level “is like psychological warfare for many,” said Lingxiao Yang, chief operating officer at crypto quant firm Trade Terminal. “It only took about a month for bitcoin to go up from around $14,000 to the new all-time high.”

But Yang also said that this emotional element has largely been reflected on the retail investors’ side, while more institutions are in the “buy the dip” mindset.

Market fundamentals are also weighing on bitcoin. Data from crypto analytics site CryptoQuant indicate major bitcoin holders, or whales, have not been withdrawing bitcoin from exchanges.

“The fact that whales don’t withdraw means that BTC is available for selling,” Ki Young Jun, chief executive officer of CryptoQuant said in a tweet. “If whales think the price will go up, they’ll withdraw BTC a lot.”

Further evidence of increased selling pressure near $20,000 is that a growing number of “wrapped” bitcoin have been “unwrapped” from the cooling decentralized finance (DeFi), according to Denis Vinokourov, head of research at Bequant.

When the Ethereum-based DeFi space was garnering all the attention in the past summer, bitcoins were tokenized (or “wrapped”) on Ethereum. At one point there were more bitcoins being wrapped on Ethereum than bitcoins being created by bitcoin miners. To some extent, that may have been simply because bitcoin’s price was doing reasonably well over the summer, more than doubling from its March 17 sell-off low of $3,867.09.

“It is worth remembering that the initial minting was done at much lower absolute [pricing] levels, and taking some profit and locking assets in the future makes sense from a prudency standpoint,” Vinokourov said.

Read more: Bitcoin Price Could Hit $50K in 2021, Bloomberg Analysts Say

On the buy side, the new bitcoin investors may be “agnostic” regarding exactly where they are purchasing in the range between $15,000 and 20,000, according to Vishal Shah, founder of derivatives exchange Alpha5.

Buyers “are not concerned about the next 300 or 400 points, or even 1,000 points,” Shah said. “It’s about the trajectory of things.”