The South Sea Company was estimated to be an extremely profitable trade organization, and potentials flocked in the early 18th Century in order to buy shares in the company. Bankers had stated that the Company can't fail, as it was granted exclusive rights to trading with Spanish Colonies in South America and the West Indies. In exchange for this arrangement, the South Sea Company just had to take on all of England's war debts and pay them off. Simple enough.
As investors poured in, the future of the South Sea Company looked promising despite the fact that the amount of money the company was going to bring in wasn't very high. The shares continued to rise, until one day, they plummeted. All the investors seeking fortune began to sell their shares for much less than what they bought them for, only making the drop in shares even greater.
The British Parliament was frustrated that a company with such potential was able to crash and burn so quickly. In fact, Parliament was so frustrated that they suggested tying all bankers in sacks and throwing them into the River Thames!