Shares of Tesla Inc. notched their longest losing streak in more than two months, down for a fourth straight session and ending the week off 7.6%.

The stock was the second-worst performer on the Nasdaq-100 NDX, -1.29% on Friday, suffering its lowest close in two weeks. Over the four-day losing stretch, shares fell more than 7%, tipping the stock to monthly losses of more than 1%.

Tesla TSLA, +4.42% shares on Monday closed at a record $385, supplanting a previous all-time close of $383.45 in June.

On Tuesday, analysts at Jefferies started their coverage on the stock, siding with the bears: They rated the shares their equivalent of sell and forecast the company to lose money at least until 2020, one year past what other analysts have predicted for Tesla.

See also:Tesla will be a money-losing business until 2020, analyst says

The Justice Department on Friday said that SolarCity, which Tesla bought last year, has agreed to pay about $30 million over government allegations it had inflated solar-installation costs to secure larger payments. A spokesman told The Wall Street Journal the company had valued the systems correctly.

Earlier in September, Tesla Chief Executive Elon Musk tweeted that the company’s semi truck would be unveiled on Oct. 26, calling the commercial freight truck a “beast.” The truck’s unveiling had been expected for this month.

A weak September would come on the heels of a 10% gain for the stock in August, preceded by 11% losses in July.

August’s optimism was highlighted by a successful launch of the Model 3, Tesla’s first sedan aimed at the mass market.

Related:Tesla’s stock surges after analyst warns it is a mistake to bet against Model 3 ramp

After the glow of the unveiling, however, Tesla has had to deal with concerns it wouldn’t bring the sedan’s production to meaningful numbers fast enough for some of its investors.

Shares of Tesla have gained 64% so far this year, six times the gains for the S&P 500 index. SPX, -1.11% They have underperformed the benchmark, however, in the past three months, with Tesla down 8% versus gains of nearly 3% for the S&P.