The S&P 500 index on Friday finished above a chart level that delivered a dose of encouragement to stock-market bulls arguing that the U.S. bear-market bottom is in, though technical analysts warned that it might not be a signal to go all in on equities. The S&P 500
SPX,
+1.73%
on Friday rose 1.7% to close at 4,280.15. The finish above 4,231 would mean the large-cap benchmark has recovered — or retraced — more than 50% of its fall from a Jan. 3 record finish at 4796.56.
“Since 1950 there has never been a bear market rally that exceeded the 50% retracement and then gone on to make new cycle lows,” said Jonathan Krinsky, chief market technician at BTIG, in a note earlier this month.
Stocks rose across the board Friday, with the S&P 500 booking a fourth straight weekly gain. The Dow Jones Industrial Average
DJIA,
+1.27%
advanced more than 420 points, or 1.3%, on Friday and the Nasdaq Composite
COMP,
+2.09%
rose 2.1%. The S&P 500 attempted to complete the retracement in Thursday’s session, when it traded as high as 4,257.91, but gave up gains to end at 4,207.27. Krinsky, in a Thursday update, had noted that an intraday breach of the level doesn’t cut it, but had cautioned that a close above 4,231 would still leave him cautious about the near-term outlook. “Because the retracement is based on a closing basis, we would want to see a close above 4,231 to trigger that signal. Whether or not that happens, however, the tactical risk/reward looks poor to us here,” he wrote. The stock market’s bounce off the June lows has encouraged bulls looking for signs the bear-market lows have been established. History, however, shows that bear-market rallies can be quite strong, leaving investors wary the summer bounce could prove to be yet another head fake, even with the S&P 500 clearing the 50% retracement hurdle. Related: Nasdaq bull market? A history of head fakes says it’s too early to celebrate. What’s so special about a 50% retracement? Many technical analysts pay attention to what’s known as the Fibonacci ratio, attributed to a 13th century Italian mathematician known as Leonardo “Fibonacci” of Pisa. It’s based on a sequence of whole numbers in which the sum of two adjacent numbers equals the next highest number (0,1,1,2,3,5,8,13, 21 …). If a number in the sequence is divided by the next number, for example 8 divided by 13, the result is near 0.618, a ratio that’s been dubbed the Golden Mean due to its prevalence in nature in everything from seashells to ocean waves to proportions of the human body. …