Crypto ETF investors pulled $541.1 million from spot Bitcoin funds and $63.2 million from Ethereum products the day before the U.S. presidential election, according to data from U.K.-based asset manager Farside Investors.

The $541.1 million Bitcoin ETF exodus was only surpassed by the $563.7 million in outflows on May 1, according to Farside.

The withdrawals marked a sharp reversal from the previous week, when Bitcoin ETFs attracted net inflows of $2.2 billion. Those gains came as crypto's favored candidate Donald Trump's prospects to regain the U.S. presidency looked bright. But the momentum shifted over the weekend to Kamala Harris.

"I don't think the crypto market is predicting a Trump loss, but I do believe bitcoin outflows can be attributed to pre-election positioning, meaning that traders may be taking some money off the table to lock in some gains as BTC is up more than 12% in the past month," said Kent Thune, research lead at etf.com.

Bitcoin, the largest cryptocurrency by market value, fell slightly on Monday, although it more recently returned to its perch of last week above $70,000, a nearly 4%, rising nearly 4% over the past 24 hours, according to crypto data provider CoinMarketCap. The increase came as investors sent equities and other risk-on assets higher. Tuesday fund flows were not available at the time of publication.

On Monday, BlackRock's iShares Bitcoin Trust (IBIT) was the only fund in the category to buck the trend, attracting $38.4 million in inflows. The largest single-day outflow came from the Fidelity Wise Origin Bitcoin Fund (FBTC), which experienced outflows of $169.6 million.

The ARK 21Shares Bitcoin ETF (ARKB) recorded outflows of $138.3 million on election eve, while the Bitwise Bitcoin ETF (BITB) had $79.8 million leave the fund, according to Farside data.

The total year-to-date flows remain strongly positive for spot Bitcoin ETFs at $23.7 billion, Farside data shows. The funds now manage about $60 billion in assets.

Some crypto market observers attributed the outflows to wider market trends.

"Current inflow trends are largely being driven by market conditions and investor sentiment rather than immediate political development," wrote Joe DiPasquale, CEO of crypto fund manager BitBull Capital, in a note to etf.com.

But DiPasquale also noted that "large purchasers are waiting for additional information, including the election results as well as whether the Bitcoin price rises over $73K," its current resistance line and near its all-time high.