Cryptocurrency exchange Kraken is exploring the possibility of raising up to $1 billion in debt as it prepares for a potential IPO.Kraken is working with Goldman Sachs and JPMorgan Chase and reaching out to other banks and lenders to gauge interest.The debt raise is aimed at fueling Kraken's growth strategy and the company is also considering an equity raise as part of its capital strategy.Kraken recently agreed to acquire retail futures trading platform NinjaTrader in a $1.5 billion deal and is looking to expand its operations.