This is called a half-victory for both sides. Democrats have resumed the House of Representatives to the Republicans who can put a drag on the President but have not had the blue tide hoped for. They even lost two seats in the Senate which reinforces Trump's claim for victory.
Concretely, this result will not prevent Trump from continuing its trade war with China but will, on the other hand, prevent it from passing new tax reforms which could create tensions for the next two years.
Regarding the markets, the threat of the “blue wave” has officially passed which reassured investors. The European stock market opened slightly higher this morning. The US Dollar has weakened compared to the Euro but there is no great movement following these results.