Will DRW's departure cause a sustained drop in natural gas prices?
Probably not sustained unless the firm was a dominant position holder. Short-term volatility is more likely as their positions are liquidated, but the market will rebalance if fundamentals remain unchanged.
How large could the impact be on Henry Hub futures?
Without knowing the notional size of DRW's trades, it's hard to quantify, but any forced exit by a significant player can cause outsized moves, especially in less liquid contract months.
Should traders buy or sell natural gas on this news?
Tactically, monitoring for a spike in volume and intraday price swings could present opportunities, but direction depends on the nature of DRW's positions; risk management is key.