China might be the world’s biggest auto market, but when it comes to General Motors’ bottom line, the United States is still solidly No. 1.

The Detroit-based manufacturer of Chevrolet Silverado pickup trucks and Cadillac CT6 sedans said Wednesday it earned a record profit of $9.7 billion in 2015 and beat Wall Street estimates in its fourth-quarter numbers.

"It was a strong year on many fronts, capped with record sales and earnings, and a substantial return of capital to our shareholders," GM’s Chief Executive Mary Barra said in the release of the earnings statement.

The company reported $6.3 billion in fourth-quarter net income, or $3.92 per diluted share, up from $1.1 billion, or 66 cents per diluted share in the same period of 2014. Adjusted earnings per share rose 17 percent to $1.39 from $1.19, beating the Wall Street estimate of $1.21 per share.

A major portion of GM’s fourth-quarter profit is attributable to a $3.2 billion tax benefit from GM’s European operations. The company’s net income from operations was $3 billion in the fourth quarter.

General Motors followed other automakers' stock prices down on Wednesday as investors weigh the possibility that six consecutive years of U.S. auto sales growth could be winding down. GM stock fell 4.6 percent to $28.29 by midday Wednesday. The stock is down 15 percent since the start of the year, well below the S&P’s 7.4 percent drop in the same period.

Digging further into GM’s recent full-year earnings statement shows just how much GM depends on American demand for its trucks and SUVs. While GM is struggling in South America and Europe, North American growth checked in at 5 percent for 2015 and 3 percent for the Asia-Pacific/Middle East/Africa regions.

GM is a major presence in China, but the numbers show how little the company actually makes from its dozen joint ventures in the world’s largest auto market. GM doesn’t break out net income from China, but it makes up a lion’s share of sales and revenue for the Asia-Pacific/Middle East/Africa region. The company earned $1.4 billion in these emerging markets, compared to $11 billion in North America, income largely comprised of U.S. vehicle sales.

In the U.S., Chevrolet crossovers — small-engine sport utility vehicles built on car platforms — jumped 23 percent last year compared to 2014 while demand for Chevrolet sedans plunged 13 percent. GM crossover vehicles are still less popular in terms of sales volume compared to sedans and trucks, but they’re climbing fast.

Meanwhile Chevy trucks, which include pickups like the Chevrolet Silverado and large SUVs like the Suburban, overtook Chevrolet sedans in unit sales last year to become the most popular vehicle types for General Motors. In essence, GM cars are falling in demand quickly while GM crossovers are moving in to take their place behind GM trucks and big SUVs.

Buick sales in the U.S. fell, but they made considerable gains in China, where the brand has historic cachet and is viewed as more of a luxury brand than it is in the U.S. Cadillac sales jumped 10 percent in China, to about 87,000 units, compared to a 5 percent increase in the U.S., to about 175,000.

GM saw a noticeable rise in demand for Baojun-brand cars and minivans. Baojun was created in 2010 with GM’s Chinese partners SAIC and Wuling Motors as a lower-priced alternative to Buicks and Chevrolets. While Baojun still trails behind Wuling, Chevrolet and Buick vehicles in the Asia-Pacific/Middle East/Africa region, sales nearly tripled compared to 2014. Wuling and Chevrolet sales declined while Buick demand grew 13 percent to just over a million units.

GM is the second-biggest foreign automaker in China, where it exports low-priced vehicles to other emerging markets, but Wednesday’s earnings report showed that the U.S. has become even more important to GM’s profitability.