Speculative investing weakened the stability of the stock market because people were "over-investing" in companies--meaning that that companies were becoming highly over-valued, which led to an economic "bubble" that eventually popped in the Crash of 1929.
The Hittites were allegedly the first society who used chariots as war machines with javelinists or bowmen which enabled them to win battles as such a war device wasn't in use at the time by other nations. However, there has been some dispute whether the Hittites were actually the first society who used chariots as a means of war.
Similarities between Japanese and European feudalism include a social system of various classes with little possibility of mobility from one class to another, the proffering of allegiance in exchange for protection, a warrior class with a code of honor and a peasant class tied to the land. Both societies also had clergy that functioned outside the normal feudal system.