Chinese social media and video game giant Tencent became more valuable than Facebook on Tuesday as investors sent the company soaring into the top five of the world's biggest firms.

Tencent's Hong Kong-listed shares have doubled in value this year, and on Monday it became the first Asian company with a market capitalisation of half a trillion dollars.

By the end of the trading day on Tuesday, Tencent's outstanding shares were worth a combined 4.08 trillion Hong Kong dollars ($523 billion), surpassing Facebook's $519 billion.

Despite its stratospheric climb, Tencent is still some way behind the world's most valuable company, Apple, which is currently valued at $873 billion.