Currently the Democrats hold 47 seats in the Senate (including the two independents who caucus with them, Sanders and King).

This resolves YES if they GAIN seats (including any independents that caucus with them, or that a media consensus views as likely to caucus with them, or predominantly aligned with the democrat party and their views).

If there are special elections or some sort of party flips of members between now and the election, this market will still require the democrats to gain seats during the midterms. That is to say, let's say one republican flips to being a democrat and there are then 48 dem seats in the senate, then they will have to have 49 seats after the midterm elections.

If there are some sort of election-rigging claims, or the senate is disbanded, or the Trump admin stops democratic senators from being seated, or some other hijinxes ensue, I will use my judgement to ensure a fair resolution. Thus, I will not bet in this market.