The relentless sell-off in stocks started marking some grim milestones this past week. The S & P 500 briefly dipped on Friday into bear market territory, trading more than 20% below its January intraday record. There's no official definition for a bear market, so investors will debate whether we are in one officially now or not. Many on Wall Street define it as what we saw on Friday — a 20% drop from an intraday 52-week high. But others want to see it happen on a closing basis before calling it a bear. Most believe we are in a bear market that began in January. The tech-heavy Nasdaq Composite fell deeper into its own bear market — now down nearly 30% from its record. The Dow Jones Industrial Average fell 2.9%% for the week, marking its eighth consecutive weekly decline. That's the Dow's first eight-week slide since 1923. The S & P 500 and Nasdaq Composite fell for a seventh straight week, losing 3.1% and 3.8%, respectively. The heavy selling comes as investors shunned risk assets on concerns over how well companies and the U.S. consumer are dealing with the recent inflationary surge. Meanwhile, the Federal Reserve has stated it will keep raising rates to quell those pressures — raising worries that tighter monetary policy could tip the economy into a recession. Here's a breakdown of why the market tumbled this week, and what pros on Wall Street think could happen next. Why did this happen: Walmart and Target earnings, Powell's comments This week's declines came after back-to-back quarterly reports from Target and Walmart, which showed both companies were struggling to cope with rising costs. "As we were reminded by Target and Walmart earnings reports this week, rising sales are no guarantee of rising earnings. Inflation may have helped the retailers' top lines, but it also meant higher-than-expected expenses and lower-than-expected margins," wrote Ed Yardeni, chief investment strategist of Yardeni Research. "In addition to cost inflation, supply-chain problems tripped up the nation's largest retailers, as did tough comparisons to last year, when federal subsidies gave consumers free money to spend," he added. Those reports set off a sharp market sell-off Wednesday, as investors feared higher inflation would eat at other companies' profits as well. The Dow and S & P 500 fell 3.6% and 4%, respectively, that day — their biggest one-day losses since June 2020. The Nasdaq, meanwhile, fell 4.7% on Wednesday, its worst daily decline since May 5. Those numbers also raised concern over the health of the consumer. Walmart said that consumers were buying fewer items, with many skipping purchases of new clothing and other goods . Target, meanwhile, said consumers were buying fewer big-ticket items such as TVs. Target shares ended the week down 29.3%, their biggest weekly drop since October 1987. Walmart 's stock dipped 19.5%, marking tis worst weekly decline since October 1974. On top of all of this, it doesn't seem like the Fed will come to the market's aid anytime soon. Fed Chair Jerome Powell said Tuesday that the central bank will keep raising rates until prices start easing from current levels. "If that involves moving past broadly understood levels of neutral we won't hesitate to do that," he said. "We'll go to that point. There won't be any hesitation about that." But some on Wall Street fear that hawkish stance could tip the economy into a recession. Guggenheim's Scott Minerd called the Fed's tightening plan "overkill," noting that: "Given the aggressive posture of the Federal Reserve, we're going to be meaningful lower this year in stocks before we find a bottom because the Fed has made it clear they do not have a 'put' on the stock market." "Unless we get something that is threatening to financial stability, they seem quite comfortable to watch the stock market go down as long as, in their mind, it's an orderly decline," he said Wednesday . What happens next: It depends on the economy Several strategists on the Street have already trimmed their year-end targets for the S & P 500, but many of them think what happens next depends on whether the U.S. economy falls into a recession. Deutsche Bank's Binky Chadha said in a note this week that the S & P 500 could tumble all the way down to 3,000 if a recession takes hold in the near future. That's another 23% lower from here. "Inflation is proving sticky and the Fed's forward guidance is for a rate hiking cycle that has historically ended in recession more often than not (8 of 11 or 73% of the time), with the Fed acknowledging and accepting this risk," Chadha said, noting that his base case is not for an imminent recession. The strategist trimmed his 2022 S & P 500 base case target to 4,750 from 5,250 . Meanwhile, Bank of America said there's a "realistic worst case" scenario where the S & P 500 falls to 3,200, with strategist Savita Subramanian noting that the current market set-up looks a lot like the one seen as the 2000 dotcom bubble was bursting. Jeremy Grantham, an investor famous for calling market bubbles told CNBC this week that today's bubble is worse than 2000 . "The other day, we were down about 19.9% on the S & P 500 and about 27% on the Nasdaq. I would say at a minimum, we are likely to do twice that," the co-founder of GMO told CNBC's Kelly Evans on "The Exchange" Wednesday. "If we are unlucky, which is quite possible, we would do three legs like that and it might take a couple of years as it did in the 2000s." The U.S. economy contracted by 1.4% in the first quarter, marking the first negative growth rate since the onset of the pandemic. Still others are more optimistic if a recession can be avoided. JPMorgan's Marko Kolanovic, who effectively navigated the markets during the pandemic, says the stock market is pricing in "too much recession risk." "If recession doesn't come through, multiple derating was already very substantial, and given the reduced positioning and downbeat sentiment, equities stand to recover from here," Kolanovic wrote this week.