Check out the companies making headlines after the bell:

Shares of CSX dropped about 2 percent after hours on Wednesday. The rail transportation company reported an earnings beat on the top and bottom line. CSX earned $1.01 per share this quarter, beating Wall Street's estimates slightly. The company's quarterly revenue was $3.14 billion. CSX also announced a new $5 billion stock buyback program.

Shares of Alcoa rose over 3 percent in after hours trading Wednesday, but its stock later gave up those gains. The top U.S. aluminium producer reported better than expected quarterly earnings. Alcoa earned 66 cents a share, beating Wall Street's estimates which were 50 cents a share. The company's quarterly revenue was $3.34 billion, slightly better than the $3.33 billion expected by Wall Street.

PG&E Corporation rose as much as 12 percent after market close on Wednesday. The stock closed positive for the day but is down over 70 percent for the month. The move comes after the company announced Monday it will likely file for bankruptcy after facing at least $30 billion in expected costs related to California's deadly 2017 and 2018 wildfires.