The next big market catalyst will be what the Fed says about its balance sheet this week

The market has reason to believe that the Fed is going to stop raising interest rates for a while. Less certain is what the central bank will do with the $4 trillion of bonds left on its balance sheet.

That latter issue is likely to take focus Wednesday when the Federal Open Market Committee releases notes from its January meeting. At that meeting, Chairman Jerome Powell and his fellow committee members made it clear that they would be “patient” with rate hikes and that for now policy tightening will be on pause.

However, while Powell indicated he would be watching how the process unfolds, there were no indications the roll-off would slow.

The Fed currently allows up to $50 billion a month in proceeds from Treasurys and mortgage-backed securities, though it does not regularly hit that number. Since the process began the bond portfolio has shrunk by more than $400 billion. The balance sheet had once stood at $4.5 trillion, the product of three rounds of bond buying — quantitative easing — the Fed instituted to lower long-term rates and pull the economy out of the financial crisis.

Market participants are now wondering how much further the Fed will go. The minutes from the meeting, which helped spark a stock market rally, will be looked at closely.

“The minutes from the two preceding meetings – November and December – included important sections on the balance sheet,” Lewis Alexander, chief economist at Nomura, said in a note. “We believe the corresponding section of the January minutes will confirm the Committee’s plans to end balance sheet normalization by end-2019.”

Several Fed officials have pointed to the end of the year as a likely point for the process to end, but even that remains in flux.

The key in the discussions thus far is the level of reserves at which the banking industry feels comfortable. The decline in the balance sheet corresponds with a lower level of reserves. Currently, banks are holding about $1.64 trillion in reserves, or nearly $1.5 trillion above the required level.

Many Fed watchers think the final level will be somewhere just in excess of $1 trillion, though some see it higher.

“Once we reach $1.1 [trillion] of reserves, the normalization is done,” wrote Jabaz Mathai, head of U.S. rates strategy at Citigroup.