Is bitcoin back? Signs pointed to price strength in Monday trading after the No. 1 digital currency by market value surged over the weekend. Here's what you need to know in cryptocurrencies for Monday, April 23.

Weekend Price Rally

Bitcoin prices soared as high as $9,000 on Sunday trading, capping a weekend of gains that saw the cryptocurrency climb to levels not seen since March 22. As prices rallied among most of the top cryptocurrencies over the weekend, the value of the digital asset market reached $400 billion briefly for the first time since early March. After dipping back below the threshold, the market's value teetered over $400 billion again Monday morning. Cryptocurrencies had gained about $100 billion in April at this weekend's highs. Trading volume also surged, reaching $8.4 billion Friday and $7.5 billion Saturday. Trading volume had only reached $8 billion one other time since March 9. While bitcoin prices have gained in recent trading, they remain about 55% off an all-time high of nearly $20,000 set in December.

Goldman Hires Head Crypto Trader

Goldman Sachs Group Inc. (GS) has hired a head of digital assets markets in a bid to gauge client interest in trading bitcoin and other cryptocurrencies. Justin Schmidt, who is 38, will join Goldman in its New York securities division as the VP and head of digital assets markets, a bank spokeswoman told ZeroHedge. Schmidt previously worked in quantitative trading and graduated from Massachusetts Institute of Technology. In late-2017, Goldman was rumored to have considered opening a cryptocurrency trading desk, but upper management denied the claim. "In response to client interest in various digital products, we are exploring how best to serve them in the space. At this point, we have not reached a conclusion on the scope of our digital asset offering," the bank said after hiring Schmidt.

Coinbase Suspends WikiLeaks

Coinbase, one of the largest digital currency exchange platforms, has suspended WikiLeaks from using its services. WikiLeaks, which is best known for publishing confidential documents, had previously allowed users to purchase merchandise like shirts and posters in bitcoin using Coinbase. WikiLeaks said on Twitter over the weekend that Coinbase notified the site that it was "in violation" of the terms of use but didn't specify how exactly.

ANNOUNCE: Coinbase has blocked the official @WikiLeaks shop from its platform without notice or explanation. You can continue to donate #Bitcoin to WikiLeaks at https://t.co/lvhoyhlqUa. #Coinbase #DefendWL #Cryptocurrency #Ethereum #BitcoinCash #ReconnectJulian pic.twitter.com/4BSS023OOk

— WikiLeaks Shop (@WikiLeaksShop) April 21, 2018

WikiLeaks said it would "call for a global blockade of Coinbase" because it is "an unfit member of the crypto community." It's not the first time WikiLeaks has been reprimanded by a financial services provider, though - Mastercard Inc. (MA) and PayPal Holdings Inc. (PYPL) have both restricted WikiLeaks on their platforms.

Monex CEO: Regulation 'Common Sense'

The chief executive of Monex Group, Oki Matsumoto, told Reuters that Japan's cryptocurrency exchanges should be regulated with closer scrutiny. Monex, which is the third-largest online brokerage in Japan, recently bought Coincheck, a Japanese crypto exchange that was hacked in an attack that cost users as much as $530 million. "Japan's exchanges do both matching and custodial services - they're close to a bank," Matsumoto said. "To someone in the financial industry like myself, it's common sense that regulations will get stricter."

Goldman Sachs and PayPal are holdings in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio . Want to be alerted before Cramer buys or sells the stocks? Learn more now.

More from Investing

Apple Doesn't Need to Hit the Panic Button on iPhone Pricing

Apple Doesn't Need to Hit the Panic Button on iPhone Pricing

Facebook Jumps on $9 Billion Buyback Plan, Bullish Note From Deutsche Bank

Facebook Jumps on $9 Billion Buyback Plan, Bullish Note From Deutsche Bank

Apple Stock Overcomes Trade Troubles to Post Gain on Monday

Apple Stock Overcomes Trade Troubles to Post Gain on Monday

Today's Action Has the Potential to Be a Turning Point

Today's Action Has the Potential to Be a Turning Point

Is Broadcom an Easy Buy After 51% Dividend Boost?

Is Broadcom an Easy Buy After 51% Dividend Boost?