Massive buying binge by the Fed in the treasury market to push the treasury yield down before the open plus a massive buying binge in the equity market to push the stock up to cause a huge gap-up to trigger short-covering rally.
Short-covering lasted all day. Without further intervention by the Fed the market should go back down tomorrow. If they decide to buy agzain, we could see another up day on Wednesday.
For Wednesday, key intraday support for NQ is at 12,700. Bearish below, next support is at 12,520, and bullish above, targeting a retest or the Tuesday high or higher.