Check out the companies making headlines after the bell Monday:
Sonic shares fell about 5 percent after the fast-food chain's full-year earnings projections came in light of expectations. The company reported third-quarter earnings of 36 cents a share, meeting Street estimates, while revenue came in at $165 million, just topping expectations of $164 million.
Small-cap banking provider Green Dot said its board authorized a $150 million stock buyback. It also agreed to renew its partnership with Wal-Mart. Green Dot shares soared more than 25 percent after the announcement.
GasLog Partners, which engages in business related to liquefied natural-gas transportation, announced a public offering of 7.5 million common units. Shares fell about 6 percent in after-hours trading
The natural gas pipeline giant Williams Companies rejected a nearly $50 billion buyout offer from Energy Transfer Equity earlier on Monday, which sent its shares up more than 25 percent during the regular session. However, the stock gave up most of those gains after hours to trade down about 21 percent.