At this time last year, some analysts and investors were worried that General Motors (GM 0.70%) was losing ground in the lucrative full-size truck segment to Fiat Chrysler (FCAU). Historically, Fiat Chrysler's Ram brand had held the No. 3 spot for full-size pickups in the U.S., but Ram pickups outsold the Chevy Silverado, GM's main full-size pickup model, by 5% in the first quarter of 2019.

Even then, the concerns seemed overblown. After all, GM sells somewhat pricier full-size pickups under the GMC Sierra nameplate, and including the Sierra, the General remained well ahead of Fiat Chrysler throughout 2019. In addition, management attributed GM's market share losses in the first half of last year to supply constraints related to the transition to a new truck architecture.

Today, last year's worries that GM would fall to third place in the pickup market seem downright silly. In fact, General Motors blew past Ford Motor (F 1.36%) to retake the top spot in the U.S. pickup market last quarter, driven by a 27% year-over-year jump in Chevy Silverado deliveries.

A white Chevy Silverado driving on a dirt road

Chevy Silverado sales skyrocketed in the first quarter of 2020. Image source: General Motors.

The Chevy Silverado comes roaring back

Despite losing share in pickups during the first half of 2019, by the end of the year, GM had delivered 807,923 full-size trucks in the U.S., slightly more than the 805,135 it delivered in 2018. A stellar third-quarter sales performance enabled this ever-so-modest full-year growth.

Ram trucks still outsold the Chevy Silverado on a full-year basis. But including the GMC Sierra, GM beat Fiat Chrysler in the domestic full-size truck market by 27%. On the other hand, Ford's popular F-Series trucks remained the clear market leader, with 896,526 deliveries, 11% ahead of the Silverado and Sierra combined.

Last quarter, GM reported stellar growth in the domestic full-size truck market. Chevy Silverado deliveries soared to 144,734 units from 114,313 units a year earlier. While Ram had another good quarter, growing sales 7% year over year to 128,805 units, the Chevy Silverado is firmly back in the No. 2 spot in the United States.

Adding in GMC Sierra deliveries, GM sold 197,743 full-size trucks in the domestic market last quarter, up 28% year over year. By contrast, Ford F-Series deliveries slumped 13% to 186,562 units. Thus, while F-Series remains the top-selling truck nameplate, GM had a 6% advantage over Ford in terms of overall full-size truck sales, not to mention a massive 54% lead over Fiat Chrysler.

A red Ram pickup truck

GM's full-size truck sales far outpaced deliveries of Ram pickups last quarter. Image source: Fiat Chrysler.

Of course, easy year-over-year comparisons contributed to General Motors' stunning growth in full-size pickups last quarter. Yet the General also surpassed its Q1 2018 domestic full-size truck delivery total by 12%. Moreover, GM was still experiencing some supply constraints last quarter because of the six-week UAW strike that disrupted production last fall -- and overall auto sales tumbled last month as stay-at-home restrictions went into effect in many states.

Midsize trucks add to GM's lead

General Motors' lead in the pickup market is even bigger when one adds midsize trucks to the mix. Last year, Ford reintroduced its Ranger midsize pickup in the U.S., while Fiat Chrysler launched its new Jeep Gladiator model.

Those new models enabled Ford and Fiat Chrysler to gain share in midsize pickups at GM's expense last quarter. Ford Ranger sales more than doubled to 20,980 units. (Ranger sales were just starting to ramp up in the prior-year period.) The Jeep Gladiator also put in a solid performance with 15,259 deliveries, up from a negligible amount a year before.

Meanwhile, combined sales of the Chevy Colorado and GMC Canyon midsize pickups tumbled 36% year over year to 25,913 units last quarter. It's not clear how much of that decline was driven by inventory shortages from the strike last fall as opposed to more-permanent market share shifts. Still, GM remains comfortably ahead of Ford and Fiat Chrysler as the No. 2 player in the midsize truck segment behind Toyota Motor.

GM could be primed for a rebound

The Big Three automakers get the majority of their earnings from truck sales: particularly their full-size pickups. All else equal, the big jump in GM's full-size truck sales last quarter would translate to hundreds of millions of dollars of incremental profit.

However, the General's vastly improved position in this lucrative market segment has been mostly overlooked, as investors have become preoccupied with the impact of COVID-19 on the auto market. Indeed, auto production has been halted for several weeks and retail sales volumes are drying up as consumers stay home.

That said, automakers are starting to make preparations for resuming some production as soon as early May. GM has ample liquidity to stay solvent even if that target gets pushed back by a month or two. And while demand could remain muted for the remainder of 2020 because of the recent surge in job losses, automakers like GM are built to withstand cyclical volatility in auto sales.

GM stock has lost nearly half of its value over the past year. While the temporary challenges it faces are undeniable, the company's share gains in the domestic truck market make its competitive position look stronger than ever. That's why I'll be looking to add to my holdings of GM stock later this month.