The gap between the bitcoin price in U.S. Dollars (BTC/USD), on popular digital asset exchanges such as Binance and Coinbase, and Binance’s U.S. branch has increased dramatically this month. This has caused unease for crypto commentators who use Twitter.

Data from TradingView shows that at 09:26 UTC on Tuesday, the BTC/USD binary pair listed in Binance.US was trading at a premium of nearly $650 to its Coinbase counterpart as well as Binance’s Bitcoin-tether pair. This is a substantial increase from the premiums of $20 at the end April.

According to Twitter analyst @fewseethis who uses a pseudonym, the premium for Binance.US is likely due to market makers leaving in anticipation of regulatory actions. Market makers provide liquidity to order books.

Binance.US was under the radar in February due to trading affiliates. In March , a senior agency official said that Binance.US operated an unregistered exchange in the U.S.

“IF there’s some sort of gov’t action against Binance.US and market makers who normally do business there are aware, THEN IT’S POSSIBLE they left & there’s not enough liquidity & arbitrage possibilities are diminished,” @fewseethis Tweeted.

According to Cryptowatch, Binance.US had a heavily skewed order book at the time of press. The data showed that bids were a majority. According to Griffin Ardern from Blofin, a volatility analyst, this is a sign that the market has weakened and market makers are leaving.

The order book has an imbalance with the pending buy orders (green lines) being greater than the sold orders. (Cryptowatch) (Cryptowatch)

The chart below shows the Binance.US 2.5% Market Depth, which is a collection pending buy-and-sell orders that are within 2.5% of mid-price. The mid-price represents the average between the bid, ask and offer prices. The green line represents the number of buy orders that are pending. It is higher than red line which represents the sell orders.

When liquidity is adequate, the buy and sell sides are constantly changing but the dynamic balance is still maintained. Ardern, a CoinDesk reporter, said that the Binance.US order book was imbalanced. There were significantly more buy than sell orders. For a giant exchange such a chart is certainly abnormal. Binance.US is losing its top market makers, perhaps due to increased regulatory pressures and compliance requirements.

On Monday, Binance.US saw tether, which is the largest stablecoin in the world, rise to $1.3 and deviate from its dollar peg. The stablecoin that is supposed to follow the dollar continued to be valued at a premium on Tuesday.

(TradingView) (TradingView) On Monday, Tether surged up to $1.3 from its 1:1 dollar parity. (TradingView) (TradingView)

It is not clear why tether has appreciated. crypto enthusiasts have attributed the recent surge in USDT/USD to Binance.US BTC/USD trading at a higher price than tether-denominated pair.

Others, such as popular pseudonymous trader Byzantine General, and OPNX’s Alice, the market maker at OPNX, have said that the premium indicates withdrawal issues on the exchange.

CoinDesk contacted Binance.US to seek clarification and was still awaiting a reply at the time of publication.

Byzantine General asked: “Can’t they just withdraw from” Alice expressed the same opinion, saying that “it has to be either (at some threshold), a secret USD fee OR USD withdrawals are not working.”

Sheldon Reback is the editor.