The window has been largely overshadowed by the Blues’ search for Danny Cowley’s successor, which finally came to an end on Friday.
Nonetheless, Ryley Towler represented the first purchase made by Pompey this month after he joined for an undisclosed fee from Bristol City on January 6.
And in John Mousinho’s first day in charge, he was able to complete the capture of Matt Macey on loan from Luton to replace Josh Griffiths.
But how does the Blues’ business in the window compare to the rest of League One?
We’ve taken a look at which club has made the most acquisitions this January so far as managers look to prime their squad for the remainder of the campaign.
NOTE: Sheffield Wednesday, Port Vale, Shrewsbury and Wycombe have all been excluded from the list as they’re yet to register a signing.