J.P. Morgan analyst Doug Anmuth cut his rating on Twitter Inc. shares TWTR, +2.03% to neutral from overweight on Thursday, writing that the company faces numerous risks from the COVID-19 outbreak. Shares are off about 2% in premarket trading. "Twitter's near-term revenue decline could be steeper than for others given ad challenges coming into the crisis, heavy dependency on product launches/events/sports, and high exposure to brand advertising," he said. The company was already dealing with some ad-platform challenges before the crisis began. While the clamoring for information during the pandemic has been good for Twitter's user numbers, the company "is demand constrained, not supply constrained" even in normal times, from an advertising perspective. He expects that the company could still increase operating expenses while facing revenue pressure. The stock has dropped 20% over the past three months as the S&P 500 SPX, -1.11% has declined 16%.