Enron

In 1985, Enron was formed by a merger between Houston Natural Gas Company and InterNorth Incorporated. Enron was a company focused on energy, they were energy suppliers and traders. Enron was a fairly successful company that benefited by the growing market thanks to the dot com boom, as well as the stock market doing well in general. However, this company eventually became famous for the corporate fraud that happened after Enron started to lose momentum.
Enron had been using a form of accounting called mark-to-market accounting. This form of accounting let the company predict what their assets and liabilities would be in the future. This would allow them to publish assets that the believed they would obtain. If they created a new power plant that was going to generate thousands of dollars in profits, they could report that they would gain those profits, despite not being certain or having this money on hand. Already, this was a problematic practice as Enron could guess and lie about the strength of their company to investors to better their stock.
With this practice, Enron was able to masquerade as a perfect company. They shared their credit and reputation with potential investors and business partners to make them believe they were working with pros. This led them to be coined the Most Innovative Company by Fortune for 6 years in a row. Now, Enron surely must have had some failures, so had did they look like such a profitable company.
Whenever Enron had a building or operation that was making less than projected profits, the numbers on their books they were showing to the world, they transferred it to an off the books corporation where the losses went unreported. This way they could write off losses and still be a perfect and profitable company. Enron did this frequently, and by 2000, the company wasn’t doing so well. Companies would assume poor assets, and would be compensated in stocks which would rise in the future, so everybody was making money. This didn’t continue, as in 2001, the company’s management changed and the stock fell to a 52 week low, prompting the SEC to investigate.
The SEC investigated Enron, and found that the company had hid from the public the fact that they had losses of $591 million, as well as $628 million in debt. This shocked stockholders and crippled the stock. Enron soon fell apart and had to file for bankruptcy. Enron tried their best to cover this up, and was slammed by the SEC with many charges.
In June 2002, the firm was found guilty of obstructing justice for shredding Enron's financial documents to conceal them from the SEC. The founder and CEO were convicted on many counts of fraud and conspiracy. Many people who were in on the operation were convicted for insider trading as well. Overall, this once powerful company was found to be a fraud, and was punished severely because of it.
There was much that came out of the Enron scandal than just punishments. The Sarbanes-Oxley Act was passed, which worsened the consequences for destroying, altering, or fabricating financial statements, and for trying to defraud shareholders. The Act was paired with more regulation on financial institutions to prevent fraud from happening again.

Source: https://www.investopedia.com/updates/enron-scandal-summary/