A reverse stock split, or stock merge, consolidates multiple shares in a given company to form a smaller number of more valuable individual shares.
For example, an investor who owns 10 shares valued at $1 each would only have one share after a reverse split of 10-for-1, but that 1 share will now be valued at $10.
Whilst a reverse stock split does not directly impact a company's value (only its share price), it can signal that a company is in distress, since it raises the value of otherwise low-priced shares. In extreme cases, a company may even need to use a reverse stock split to avoid being categorized as penny stock.