The world’s largest digital currency has risen more than 12% since the beginning of June. On Wednesday, its price topped $30,000 to hit its highest level since April 14, CNBC reports. 

Market players have attributed the jump to the news that U.S. asset management giant BlackRock had filed for a spot bitcoin exchange-traded fund tracking the market price of the underlying asset.

While that may be part of the reason, the outsized moved can be put down to another factor beyond the news flow surrounding large institutions taking steps to embrace bitcoin or other digital assets.

Crypto “market depth” has been sitting at very low levels this year. Market depth refers to a market’s ability to absorb relatively large buy and sell orders. When market depth is low and big players put in orders to buy or sell digital coins, prices can move in a big way up or down, even if the orders are not that huge.

Market depth is a measure of liquidity in a market.