Municipal bond mutual funds in the period ending Feb. 9 saw heavy withdrawals for the 13th consecutive week.

The outflows were larger than in the previous week, breaking a two-week trend of moderation following the historic outpourings seen between November and mid-January.

Muni mutual funds that report their figures weekly posted a net outflow of $1.16 billion during the week ended Feb. 9, according to Lipper FMI.

That follows outflows of $1.07 billion and $1.90 billion in the previous two weeks. Outflows peaked at a record $4 billion during the week ended Jan. 19. The four-week moving average of outflows is now $3.11 billion.

The past 13 weeks of outflows totals $37.7 billion, or more than one-third of the $101 billion of inflows in the 22 months before that.

Josh Rudolph, municipal strategist at JPMorgan, said this week’s outflows reinforce the concerns harbored by some investors regarding valuation.

“There’s a quiet tug of war going on between the bull camp of investors who are afraid to sell because they’re worried that bonds will be tough to replace at these levels, versus those in the bear camp who recognize that we haven’t sold off the way Treasuries have so tax-exempts might back up a bit from here,” he said. “This week’s continued outflows support the latter guys.”

The yield on the benchmark 10-year Treasury note shot up 37 basis points from Jan. 28 to 3.70% on Thursday, while the gilt-edged tax-exempt 10-year climbed just 7 points in the same period to 3.38%, according to Municipal Market Data.

Mutual funds marked down the value of their holdings by $1.77 billion, based on market value, during the week. Total municipal fund industry assets fell $3.76 billion to $463.3 billion.

The avalanche of selling that began in November has forced mutual fund managers to sell bonds to raise cash to meet redemptions.

One reason outflows have moderated in recent weeks is that new issuance in the muni market has declined, which has helped to cap yields.

The $12.2 billion of debt floated by state and local governments last month was the lightest in a decade.

If issuance kicks up, there’s a concern bond prices could fall and prompt further redemptions.

State and local governments are slated to sell $6.1 billion this week, more than double the $2.94 billion issued last week but still below the $8 billion average.