Uber Technologies Inc. shares /zigman2/quotes/211348248/composite UBER +4.92% slid 2% premarket Monday, after CNBC reported that the ride-sharing and food-delivery company is planning to cut spending on marketing and incentives and slow hiring, citing an email sent by CEO Dara Khosrowshahi to staff on Sunday. "It's clear that the market is experiencing a seismic shift and we need to react accordingly," Khosrowshahi said in the email, according to CNBC. The company will now focus on free cash flow as a measure of profitability, instead of adjusted EBITDA, which is an adjustment of an already adjusted number that is often used by unprofitable companies as a measure of progress. To address the shift in economic sentiment, Uber will treat hiring as a "privilege," Khosrowshahi said. "We will be even more hardcore about costs across the board." The email comes after Uber last week posted first-quarter earnings showing a loss of $5.9 billion, far wider than the $108 million loss posted in the year-earlier period. The losses were mostly due to the decline in investments in stakes in Grab Holdings Ltd. /zigman2/quotes/222950675/composite GRAB +12.61% , Aurora Innnovation Inc. /zigman2/quotes/226576913/composite AUR +8.42% and Didi Global Inc. . On the earnings call, Khosrowshahi tried to distance the company from its main rival Lyft Inc. /zigman2/quotes/208999293/composite LYFT +3.12% , which saw its shares take a beating after its guidance disappointed and it said it was having challenges finding drivers. Uber shares have lost 38% in the year to date, while the S&P 500 /zigman2/quotes/210599714/realtime SPX -0.37% has fallen 13%.