Shares of Target Corp. /zigman2/quotes/207799045/composite TGT +0.84% rocketed 18.2% in morning trading Wednesday, which puts them on track for the biggest one-day gain in its history, after the retailer reported better-than-expected fiscal second-quarter results and raised its outlook. The stock was trading well above the Sept. 10, 2018 record close of $89.26 and all-time intraday high of $90.39. The stock's percentage gain would be bigger than the current record rally of 17.8% on Oct. 28, 2008. Target went public in October 1968. The current price gain of $15.61 is adding about $8 billion to the retailer's market capitalization, which would lift the market cap to about $51.9 billion. That's still well below the market cap of rival Walmart Inc. /zigman2/quotes/207374728/composite WMT -0.04% of $323.1 billion. Target's stock has gained 2.7% over the past 22% over the past months, while Walmart shares have advanced 18% and the Dow Jones Industrial Average /zigman2/quotes/210598065/realtime DJIA -0.19% has tacked on 1.5%.