Tesla bulls bought precisely what they wanted final week: blowout second-quarter figures from the electrical automobile maker that helped justify a tripling within the firm’s share price to this point this yr.However the market response has as soon as once more left traders and analysts puzzled. As an alternative of powering but increased after outcomes that handily beat Wall Street estimates, Tesla shares suffered their first two-day run of declines in a month, shedding greater than a tenth of their value.The reverse course was an indication that the momentum driving a handful of US share costs continues to be poorly understood, and acts as a possible supply of volatility for a broader stock market dominated by a small secure of firms.“We have not been able to identify where that extraordinary level of volume is coming from, whether it’s quants, index [trackers], options, other derivatives, retail, momentum [traders],” mentioned Adam Jonas, the analyst who covers Tesla at Morgan Stanley. “There are forces at work bigger than Tesla.”Tesla’s fortunes have been the speak of Wall Street buying and selling desks and web message boards for the previous 4 months as its stock surged in value; this month it briefly grew to become the 10th most respected publicly traded firm within the US, surpassing JPMorgan Chase. Retail traders have piled in and buying and selling volumes in choices — which give customers the suitable to purchase at a hard and fast price in future — have ballooned. Momentum alone has grow to be an growing draw for some traders, who depend on the idea {that a} stock’s robust beneficial properties over the previous few months portend higher buying and selling income sooner or later, no matter how an organization’s enterprise is definitely performing.Tesla is on the centre of that technique and is now one of many largest elements in momentum funds after its stock rocketed this yr. However that alone can not account for the complete scale of the rally, which had puzzled even Tesla executives, in accordance with one adviser to the corporate. The corporate’s outcomes final week have been speculated to vindicate these traders who had pushed its shares to a good-looking ratio of 310 occasions anticipated 2020 earnings on the prospect it might ship on its long-touted targets to revolutionise journey. It delivered its fourth quarterly revenue in a row, that means it may very well be thought-about for inclusion within the S&P 500, serving to it to draw new demand from index-tracking funds.Whereas the stock initially climbed on the outcomes, the momentum that had earlier helped elevate Tesla shares rapidly died out. After falling 5 per cent on Thursday, they slid 6.three per cent on Friday, even after credit standing company Moody’s upgraded its view on the corporate.The slide — which was adopted by a bounce in early buying and selling on Monday — cuts to the centre of a debate on whether or not the market is behaving rationally. “There is a lot of exuberance,” mentioned Chris Murphy, co-head of derivatives technique for Susquehanna Monetary, a buying and selling and expertise agency. “It’s amazing to go from a global depression to a stock market bubble in three months.”Valuations of expertise teams have climbed about 15 per cent this yr, serving to to gasoline each momentum funds and the broader market. The beneficial properties relied partially on the narrative that teams comparable to Amazon, Microsoft and Netflix would in the end be beneficiaries of the pandemic, and their rise has strengthened their sway over market cap-weighted indices such because the S&P 500, leaving the entire index weak to swings increased or decrease primarily based on the fortunes of a small group of firms.The price-to-earnings ratio — a standard measure of valuation — of tech teams within the benchmark S&P 500 US stocks index now sits on the highest degree in additional than a decade. The rise has largely been spurred by stimulus from the Federal Reserve, which by way of bond-buying programmes and deep interest-rate cuts has prompted traders to shift out of haven sovereign debt and into riskier securities, together with stocks. The low rates of interest themselves have elevated the attraction of firms having fun with fast progress, which incorporates teams comparable to Tesla and the tech giants. Tesla and different widespread momentum stocks have additionally been among the many favoured trades on buying and selling apps comparable to Robinhood which might be geared toward beginner stock pickers. Greater than half 1,000,000 Robinhood accounts now personal a stake in Tesla, a document excessive. They’ve been patrons even when its stock has retreated, signalling not less than one supply of demand for Tesla shares has endured.Portfolio managers just lately warned that the wager on the tech sector was a crowded commerce, and strategists at Citi Personal Bank on Friday cautioned that it was “almost impossible to predict where the top will be . . . while momentum and ‘fear of missing out’ pushes asset prices too far”.“The frothiness of this market has been worrisome for a couple of months now,” mentioned James Wong, a portfolio supervisor at Payden & Rygel, a fund supervisor primarily based in Los Angeles. “It won’t take a lot to change market sentiment.”