13 December 2019: US and China announce a phase one trade deal

After 18 months of escalating tariffs, the US and China announced a phase one trade agreement, with China pledging to buy more American goods and the US scaling back some planned tariffs. Stocks, which had swung for months on every trade headline, touched record highs. Within weeks the deal was overshadowed by a virus spreading in Wuhan, and China fell far short of its purchase pledges.

The lesson: Markets often rally on the announcement of a deal, not on whether it is fulfilled.