3. Taser
The story in the early 2000s was that every police officer would replace their gun with a Taser. In mid-2003, the stock price of Taser, now Axon Enterprise (AXON -0.52%), skyrocketed from around $2.50 per share to more than $25 per share by mid-2004. That gun replacement story turned out to be of the "too good to be true" variety, and, by 2005, the stock's price had collapsed. The peak stock values reached in 2003 and 2004 were not reached again until 2015 following a significant turnaround effort in 2013.
4. Bitcoin
Although not actually a stock, you can argue that Bitcoin (BTC -1.61%) is the No. 1 story in the financial sector right now. Companies with any Bitcoin-related exposure -- like Tesla -- trade at elevated multiples, and the value of Bitcoin itself has increased by more than 500% during the past year. There are multiple stories related to cryptocurrencies and blockchain technology, one of which is the possibility that Bitcoin will eventually replace fiat currencies as the most common form of money.