Before the Fed decision, all eyes will be on this big Treasury debt announcement Wednesday

Auctions of government debt, normally routine events for the Treasury Department, have suddenly become very important to financial markets.

With debt, deficits and bond yields all surging, investors are watching closely how the government will go to market with its borrowing needs.

Both bond and stock markets have been volatile amid fears of oversupply at a time when the Federal Reserve is keeping monetary policy tight, and as investors are demanding a premium for interest rate risk and geopolitics is posing various wild cards.

That’s why an announcement Wednesday on refunding, entailing the size…