The last three years have been tumultuous ones for Tesco PLC (TESO). Starting in January 2012, the UK’s largest supermarket chain issued its first profit warning in two decades. Later on it reported 2012 as its first full-year drop in profit in 19 years. The downward spiral continued as Tesco reported another full-year profit loss for 2013. In July of last year, CEO Philip Clarke was replaced by Dave Lewis, who had come over from Unilever, to try to initiate a turnaround.

Things didn’t go well to start for Lewis. Less than two months after starting, Tesco announced it had overstated profits by over £263 million over the previous three years. With promises of a turnaround being set in motion, Tesco took another blow this week when it reported a full-year loss of £6.38 billion for 2014—the biggest loss in company history and one of the largest in the UK’s corporate history. That’s quite a change from the record £3.8 billion profit the company netted in 2011.

According to the BBC, falling property values of its UK stories accounted for £4.7 billion of the loss. The company plans to close 43 of its struggling stores and has scrapped plans to build 49 new stores.

Kitchen sinking to spur growth

Despite the bomb Tesco dropped on investors, its outlook may not be as bad as you think. It seems as Dave Lewis is preparing Tesco for its turnaround by kitchen sinking—finding all the bad stuff buried deep in the company’s balance sheet and adding it all together for one big loss to get it over with. According to Reuters, “The sheer size of the loss reflects a healthy corporate acceptance of the fundamental changes in Tesco’s markets.”

Not out of the woods

During this whole mess, Tesco has actually been able to slow the bleeding a little. Declines in both comparable sales and operating income have slowed over the last quarter of the year. But there’s still much work to be done. Despite seeing “early encouraging signs” of an upturn, “the most important vital sign is that more people are coming in and there are more transactions. That’s pretty good but it’s just the start. There is so much more to do,” Lewis said.

Additionally, Tesco is still under investigation by the Serious Fraud Office for its overstatement of income. This week, the company announced it found another £60 million in misstatements from previous years as a result of an audit of its operation in Ireland.

Should we believe in Tesco?

Though there have been encouraging signs, as Lewis put it, one quarter does not a turnaround make. It could be said that Warren Buffett doesn’t believe in Lewis’ turnaround plans, as his company Berkshire Hathaway dumped 75% of its stake by March after it lost $678 million last year for its holding on the company. Right now there are simply too many reasons not to believe that investors should be patient and wait until they see more positive reinforcement before jumping on the wagon.