Edit 26/2/24: The Hungarian parliament has finally voted to allow Sweden to join NATO but this still needs to be ratified by the Hungarian President, and that position is currently vacant. Orban could delay the naming of a new president precisely to prevent Sweden from joining, and for this reason this market is not resolved just yet 

Hungary could let Sweden join NATO at any time, and they are being pressured to finally relent

Clarification: This market will resolve as "yes" if, by the end of February, the Hungarian government doesn't prevent Sweden from joining NATO in any way 

If, on the contrary, by the end of February the Hungarian government is still blocking Sweden from joining NATO in any way, it will resolve as "no"

This means that even if they vote to allow Sweden into the alliance but they still manage block it in some other way, it will resolve as "no"