Donors have poured a record amount of capital into the race - all told, Republican and Democratic candidates are expected to spend some $5 billion, according to early projections. The 2018 midterms will be remembered for the surging interest among female voters (much ink has been spilled about how white women betrayed their fellow women by largely favoring Trump in 2016) and the 256 women who won major party primaries in races for the House and Senate.

With polls opening at 6 am in most East Coast states, we've put together a summary of bellwether races that political analysts - and investors - will be keeping a close eye on. But just because many of these races are happening in the eastern time zone (Florida and Virginia are two early bellwethers), doesn't mean that the results will be in early. It's possible that control of Congress might not be settled until later this week (of course, the final tally could take even longer to settle if there are recounts). In fact, if the results are still close, it could come down to California and its seven competitive House races, which, in a worst-case scenario for Democrats, could take days or even weeks to finalize as mail-in ballots are counted.