Assets under management at Grayscale’s GBTC have slumped 50% due to aggressive outflows since it became an exchange-traded fund.

Even so, Grayscale is making five times the amount BlackRock is from IBIT, CoinDesk calculations show.

That’s down to GBTC’s expense ratio of 1.50%, compared with IBIT’s 0.25%.

Grayscale’s bitcoin (BTC) exchange-traded fund (ETF) is reaping higher income than its rivals even as investors flee the vehicle for lower-cost options.

The Grayscale Bitcoin Trust (GBTC), with almost $14 billion in assets under management (AUM), is earning about $205 million a year, CoinDesk calculations show. The figure is roughly five times larger than at rival BlackRock iShares Bitcoin Trust (IBIT), with $17 billion in AUM, which is raking in just $42.5 million.

The discrepancy is mainly down to fees, known as the expense ratio. Before the funds opened for trading on Jan. 11, operators jostling for customers started a price war that saw most settling on an expense ratio below 0.40%. GBTC, which existed as a trust before converting to an ETF, stood out, cutting the ratio just half a percentage point to 1.5%.

That compares with 0.20% at Bitwise Bitcoin ETF (BITB), the lowest among the five biggest issuers by assets under management. Ark 21 Shares Bitcoin ETF (ARKB) went to 0.21% while IBIT and Fidelity Wise Origin Bitcoin Fund (FBTC) set it at 0.25%.

Even as investors have withdrawn funds in search of platforms with lower expense ratios, GBTC’s head start means the cash is still flowing in. In January, it had AUM of $29 billion, according to YCharts, a financial analysis platform, and roughly 600,000 bitcoin.

The figure’s shrunk to $13.65 billion, based on multiplying net assets value (NAV) per share of $49.12 by the 278 million shares outstanding. It now holds about 220,000 bitcoin. IBIT, which holds 366,000 bitcoin, has 642 million shares outstanding and a NAV per share value of $35.13, giving AUM of $17 billion.

Neither Grayscale nor BlackRock responded to an email requesting comment that was sent before U.S. business hours.