Behind the scenes, the Rothschild Family financed both sides to the Napoleonic Wars, as they did later in other conflicts.
In addition, they had an agent, who hid when the Battle of Waterloo was going on, saw that the Coalition against Napoleon Bonaparte defeated the later, sent a letter secretly tied to a pigeon, who was trained to go to the Rothschild Family, informing it that Napoleon Bonaparte was defeated, so the Rothschild family spread the fake news as if Napoleon Bonaparte won.
As a result, people sold their stocks for very cheap prices, the Rothschild family bought the stocks, meanwhile, the real news about the true results of the battle reached Britain, so the stock exchange rocketed up, and thus the Rothschild Family became even wealthier at the expense of the people it deceived and lied to.