More than 13.3 million bitcoin (BTC) worth $388.7 billion have been dormant on-chain for at least a year, according to data tracked by blockchain analytics firm Glassnode.

The tally equals 68.54% of the circulating supply of 19,451,256 BTC and shows a persistent bias for holding the cryptocurrency for long-term gains, according to analysts at the cryptocurrency exchange Bitfinex, though some the inactive supply could include coins lost. The level hit an all-time high of 69.2% two weeks ago.

The percentage of circulating supply inactive for at least two years recently jumped to a record 56%, with 40% inactive for at least three years. Dormant coins are those that have not been spent on-chain over the relevant period. The increasing figure suggests a decline in the supply available in the market and the potential for a sharp price rally, assuming the demand side strengthens.

“This trend, indicative of the prevalent accumulation strategy prevalent amongst long-term holders, showcases a robust belief in Bitcoin’s long-term value, even amidst the notorious downturns that have characterized the cryptocurrency market over the past one year,” analysts at Bitfinex said in a note shared with CoinDesk.

“This inherent scarcity, juxtaposed with a burgeoning demand, has the potential to drive prices upward,” the analysts said. “The unwavering faith in Bitcoin paints a bullish picture for the cryptocurrency’s future. Only time will tell how these dynamics will shape the market, but for now, the sentiment is one of steadfast optimism.”

Note that the metric also overlooks the so-called financialization of bitcoin over the years.

Financialization refers to changes in the way people can invest in bitcoin. Over the years, CME’s cash-settled futures, spot, and futures-based exchange-traded funds (ETFs) have emerged as popular alternative investment vehicles that allow investors to take exposure to the cryptocurrency without owning it. These products, the so-called liquid tradeable proxies, also impact the cryptocurrency’s price.

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