Agency mortgage-backed securities gross issuance rose to $161 billion in January, up 22% from $132 billion a month earlier, the Royal Bank of Scotland ($10.33 0.62%) noted in its issuance report.

Freddie Mac issuance was up to $40 billion, or 54%, for the month, compared to $26 billion last month. 

Similarly, Fannie Mae issuance increased to $84 billion, or 28%, up from $66 billion.

Additionally, Ginnie Mae issuance posted a slight decline, falling to $37 million, or 8%, from $40 billion.

Net issuance also was up month-over-month, rising to $17.5 billion.

Approximately 98% of total gross issuance was concentrated in coupon 4s or lower.

Across the coupon stack, 3s through 3.5 coupons accounted for 63% of originations, while 3.5s through 4s make up 17%. Additionally, sub-3s  accounted for 18%.