Walmart and Macy's are diverging, and the gap could get even worse

Walmart and Macy's show off two sides of retail in wildly different months

It's a tale of two retailers: as Walmart has spiked this month, Macy's has slumped.

If Walmart is to continue higher, it needs to clear one key technical hurdle, said Matt Maley, equity strategist at Miller Tabak.

"Even though they've bounced back, it has not made a higher high yet," Maley said Wednesday on CNBC's "Trading Nation. " "The chart is making what's called a symmetrical triangle formation so the stock is going to have to rally further before we can say that's it's going to really break out from here."

Maley said Walmart would need to clear $100 to break above the symmetrical triangle formation, a pattern which suggests a consolidation period for a stock.

"That would really show that we're going to have another leg higher in the rally that began in 2015," Maley added. "It needs some more upside follow-through before we can confirm that it's got much further to go."

Macy's is in more danger of breaking lower, said Maley.

"It needs to rally almost immediately because if it continues lower and you get down towards that $20 level, you're going to move below its trend line going all the way back to 2009 and then down at $17.50 that would give it a key lower low," he said.

Stacey Gilbert, head of derivative strategy at Susquehanna, said the divergence in these two names is a good example of why active investing in this space is so important.

"A theme that we're going to have ... which will remain for much of 2019 into 2020 is you can't just buy a basket," Gilbert said Wednesday on "Trading Nation." "You've got to know your names because the stories are going to be the telling parts particularly over the next 18 months to two years."

Walmart is up 5 percent so far this year, while Macy's has broken down 18 percent.