Hang Seng futures exploded over 5% higher as after-hours trading began last night, then crashed back to unchanged as the underlying cash index hit its highest since Nov 2007 on the heels of a surge to new record highs for Chinese tech giant Tencent – which is now larger than Facebook by market cap.

Contracts for November delivery rose to 31,341 at 5:15pm for a 5.1% premium over the underlying gauge…

Hong Kong’s benchmark equity measure advanced 1.9% on Tuesday to its highest close since November 2007, as WSJ reports, one day after its market capitalization surpassed $500 billion, the company behind messaging app WeChat rallied by another 2.4% on Tuesday, lifting its market value to $523 billion.

If Tencent were in the S&P 500, it would be the fifth most valuable company by market value.

It would surpass Facebook at $519 billion as of their closing prices Monday according to FactSet.

Tencent, the world’s largest video game publisher by revenue, is best known in China for its WeChat and QQ messaging and mobile-payment apps, which are installed on almost every PC and smartphone there. The company has lifted its international profile too, with several big deals in recent years, including acquisitions of the game developer Epic Games Inc. and a minority stake in video game company Activision Blizzard.

It recently purchased a 12% stake in the Los Angeles social-media company  Snap, becoming one of its largest shareholders, Snap revealed in a filing earlier this month.

While little known outside of the U.S., Tencent along with Alibaba and search giant Baidu are China’s three big Internet companies. They have diversified beyond their core businesses in recent years, placing big bets on online video-streaming services and other entertainment plays.

“Tencent is an ecosystem, like Google or Apple,” said Muzhi Li, a Hong Kong-based analyst at Arete Research.

“It has many assets that have not monetized, like ads, payment and content, so investors have big hopes for the stock.”