capped by...

[chchkevin]

Can you help me to understand "capped by" in the following paragraph?

Months of political debate over raising the U.S. debt ceiling, followed by a downgrade of the U.S. credit rating by Standard & Poor's, and capped by a volatile week on Wall Street, all led to a theme throughout the Republican Presidential debate in Ames Iowa - how to fix the U.S. economy.

Regards
chchkevin

[Tdol]

The last of a series of connected events.