The Bitcoin (BTC), futures market is seeing the biggest money flow in over a month as traders bet on price movement amid a flurry crypto exchange-traded funds (ETFs) filings.

Over the weekend, open interest (or the number of unresolved contracts) on bitcoin futures reached over $11 billion, their highest level since last May, when Terra, the former behemoth, collapsed.

In May of last year, open interest had reached this level. (Coinalyze)

Open interest increases either indicate that money is being injected into the market, or that existing participants are increasing allocations. This metric is a good indicator of market sentiment, and can help determine the strength of price trends.

Coinalyze data shows that open interest is largely at $8 billion since late April.

The increase in bitcoin futures trading is parallel to an spike in volume, and increased buying activity in the bitcoin options market. These markets are used by sophisticated investors as a hedge against price fluctuations or to make leveraged bets.

Some market analysts say that the trend will likely continue if ETF applications by traditional finance giants like BlackRock are approved in the next few months.

In an email sent last week, Alex Adelman shared that “Bitcoin’s rally is part a larger trend signaling towards bitcoin as a distinct and established store value.”

Adelman said that the recent influx of bitcoin ETFs from institutions such as BlackRock, Fidelity and Invesco proves new regulatory guidelines will give institutions the green light they have been waiting for in order to launch bitcoin products and meet customer demand.

Oliver Knight, Omkar Godbole and others contributed to this report.

Parikshit Miishra is the editor.