By Luc Olinga Crypto exchange FTX has raised $400 million, pushing its valuation to $32 billion, a sum that will revive questions about a crypto bubble. The news will no doubt revive questions about the formation of a bubble in the cryptosphere: FTX Trading, one of the largest cryptocurrency exchanges, saw its valuation gain $7 billion in just over three months as the cryptocurrency market crashed. The crypto market has lost more than $1.2 trillion since hitting highs in early November. And the decline is expected to continue as crypto winter — a period of continuous decline in the prices of …