24/7 Wall St.

Following an announcement last week that fuel cell maker Plug Power Inc. (NASDAQ: PLUG) had received a purchase order from Wal-Mart Stores Inc. (NYSE: WMT) to supply electric fork lifts at six of the megastore’s North American distribution centers, the small company’s shares shot up 50% as of Monday night’s close. The shares added another 19% Tuesday morning as investors figure out where the company’s next big orders will be coming from.

Of course there is Walmart itself, with more than 130 distribution centers and thousands of U.S. stores, but there are other potential customers as well. Bloomberg has suggested that Sysco Corp. (NYSE: SYY), Kroger Co. (NYSE: KR) and BMW are among interested customers.

Walmart already has 535 of Plug Power’s units in use, and last week’s order will add another 1,738 to that total, all at just a handful of distribution centers. Walmart also operates more than 4,600 stores in the United States, and each one of those has at least one forklift, and most probably have more. And then there are the more than 6,000 international stores and 160 international distribution centers.

Plug Power shares were up more than 17% shortly before noon on Tuesday to $6.82, after earlier posting a new 52-week high of $7.02. The 52-week low is $0.15. Shares are up more than 4,500% from that low!