Stocks edged down on Friday amid escalating concerns over an ongoing government shutdown and continued uncertainty over growth in China.

The S&P 500 (^GSPC) fell 0.01%, or 0.38 points, as of market close. The Energy sector led declines as U.S. crude oil prices (CL=F) slipped about 2% as of Friday’s settlement, snapping nine consecutive days of gains. The Dow (^DJI) declined 0.02%, or 5.97 points, while the Nasdaq (^IXIC) declined 0.21%, or 14.59 points.

Despite Friday’s slight downturn, stock performance has so far been strong in 2019. The S&P 500 advanced about 3.5% in January as of market close Friday, after falling about 9% in December. However, stocks may well be heading back to the 2018 lows this year, according to Fundstrat’s Head of Research Tom Lee.

“In short, we believe that the crash of 2018 mirrors the mid-life crisis seen during the middle of bull markets a la 1962 and 1987 and in both bases, the bull market found its footing at the 200-week moving average,” Lee wrote in a note to clients. “That is currently [S&P 500] 2,350 or so. And both midlife crises saw a retest at that level. Is a retest in 2019 possible? Yes, but if so, we would view that as a buying opportunity.”

The ongoing U.S. China trade war has begun to chip away at some of America’s most iconic brands. Goldman Sachs (GS) downgraded shares of Starbucks (SBUX) to Neutral from Buy, citing concerns over China’s economic growth and the trajectory of comparative same-store sales for retail locations in the region. Goldman Sachs’ more bearish call on Starbucks follows Apple’s (AAPL) announcement last week that it was downwardly revising its revenue guidance for the fiscal first quarter of 2019. The tech giant said slower-than-expected hardware sales in China were a key reason for the dimmer projections, which had marked its first negative revision to revenue guidance in more than 15 years.

U.S. officials signaled that China’s trade negotiator may visit Washington, D.C., later this month. U.S. Treasury Secretary Steven Mnuchin told reporters on Thursday that “the current intent” is for Vice Premier Liu He to come to Washington later in January. This follows three days of discussions between mid-level negotiators from the U.S. and China in Beijing earlier this week. President Donald Trump told reporters on Thursday that “we’re negotiating and having tremendous success with China.”

Mnuchin noted that the government shutdown “would have no impact” on Liu’s planned visit.

The current partial government shutdown has entered its 21st day, tying it with the shutdown of December 1995 to January 1996 as the longest in U.S. history. About 800,000 federal workers are being affected by the shutdown, with about half of them furloughed and the other half forced to work without pay. Trump on Thursday walked out of a meeting with House Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer after Pelosi declined to finance the border barrier Trump has demanded as a contingency for his signing legislation to end the partial shutdown.

The ongoing shutdown has led at least one firm to lower expectations for U.S. growth going forward. JP Morgan analyst Michael Feroli on Thursday downwardly revised his first quarter annualized real gross domestic product growth projection to 2% from 2.25%.

“The primary reason for the downward revision is the economic impact of the ongoing shutdown of the federal government,” Feroli wrote in a note. “Each week the government is shut down subtracts 0.1-0.2% from quarterly GDP growth. Since the output of the government sector is not priced and sold in the market, it has to be inferred by the number of hours worked by government employees.”

Traders work on the floor of the New York Stock Exchange (NYSE) in New York, U.S., January 10, 2019. REUTERS/Brendan McDermid More

Meanwhile, the U.S. Bureau of Labor Statistics released its latest results for the Consumer Price Index on Friday, with the headline CPI registering an expected 0.1% decline month-over-month. This marks the first decrease in consumer prices in nine months, led primarily by a sharp decline in gasoline prices. The “core” CPI – excluding volatile food and energy prices – rose 2.2% in December over last year, also matching consensus expectations. The Fed often looks to the core index as a gauge of inflation in the economy compared to the central bank’s 2% target.