Ever since Twitter launched, the company turned down a few acquisition offers. The company decided to pursue the path of going public eventually. Odds are that Twitter will not go public this year. Twitter’s shares are traded on secondary markets though. Recent trades have valued Twitter at $11 billion according to Greencrest analyst Max Woolf in an interview with Forbes.
Twitter was valued as high as $8 billion in 2011. It rose to $10 billion, but then dropped again to $9 billion after Facebook’s failed IPO. Private markets should not be an indication of how a company would actually perform on the public markets.