The big fall for stocks on Wednesday has put the market at risk of an even deeper pullback, according to UBS floor director Art Cashin. The veteran trader told CNBC's " Power Lunch " on Wednesday that the stock market is near a "critical point." "I think we've yet to see the true lows. They're coming. We've got to work through it," Cashin said. Cashin said that the market taking out its previous lows, which would be 3,930 on a closing level and 3,858 on an intraday level for the S & P 500, could signal that stocks may be entering a "free fall" period. "You don't want to make a lower low. That will make a lot of people ... even more nervous," he said. Wall Street endured a brutal April, and the selling hasn't relented in May. The S & P 500 settled around 3,924 on Wednesday to set a new closing low for the year. Cashin pointed to the 10-year Treasury yield climbing above 3% and the sharp sell-off in bitcoin as events that have rattled traders in recent weeks, exacerbating the fall in stocks. "That left the fear of a systemic crisis in everybody's mind ... When you get weakness in bitcoin, the market gets edgy again," Cashin said. The declines on Wednesday were paced by the retail sector, with some of the biggest chains plunging amid rising fears about the impact of inflation, the cost of energy and the state of consumer spending. The earnings misses from Walmart and Target also shocked the market, Cashin said. Shares of Target were down almost 25% Wednesday after the retailer reported a slump in first-quarter profits and warned about a jump in costs. "Here you have two of the greatest retail merchandisers in the world, and they both admit that they missed some of this," Cashin said. But even with the potential for further declines, investors should not panic, Cashin said. "Never bet on the end of the world. It only comes once, and that's pretty good odds. But be careful," he said.