Republicans' performance has been disappointing, despite the fact that they are still certain to win the majority in the House. According to preliminary returns, the anticipated "red wave" did not occur. 

The Georgia Senate seat is expected to go to a runoff in December, and if the Democrats win the close contests in Nevada and Arizona.

Is it good for markets? In general, a split government is advantageous for businesses since it will prevent the Biden administration from enacting laws that would increase corporate taxes.

For the same reason, public spending will likely decline, which could cut inflation and benefit stocks just a little bit.

Expect conflicts in Congress: With a majority in parliament, Republicans are entirely possible to use the debt limit and resulting threat of a government shutdown to extract spending concessions & tax cuts for the wealthy, similar to how they did in 2011.