Stocks were rallying last week, and nearly 700 stocks trading on the major U.S. exchanges hit fresh 52-week highs. Freshpet (FRPT 0.82%), Trex (TREX 1.65%), and Costco (COST 0.77%) are among the more impressive stocks scoring new high-water marks. 

Freshpet, Trex, and Costco are doing a lot of things right these days. Let's go over why these were some of stocks that are earning their 52-week highs.  

A pair of dogs wearing sunglasses as they lay on a grassy field with chew toys.

Image source: Getty Images.

Freshpet

Pets have made the pandemic more bearable, and we're paying our furry friends back by treating them more like members of the family. The humanization of pets is a real trend, and savvy investors have been cashing in along the way. Shares of Freshpet have now more than doubled in 2020.

Freshpet offers all-natural refrigerated food for dogs and cats that it sells through branded coolers it installs in supermarkets, mass market retailers, and pet supply stores. It has pretty much cornered the market in this niche, since what local grocery store operator in its right mind would allow two refrigerated pet food brands install their coolers in its stores? 

Net sales rose 33% in its latest quarter. This will be Freshpet's fourth year in a row of accelerating top-line growth. It's been a great year for its shareholders, but with our attachment to dogs and cats only intensifying, making dry kibble less acceptable, Freshpet stock could be just getting started.

A Trex deck with various colorful objects including a bike, chair, and potted plant on top.

Image source: Trex.

Trex

Outdoor decking may not seem like much of a growth industry, but there's a big suburbanization tailwind helping push Trex shares higher these days. Folks are moving out of major metropolitan cities to the suburbs, and that's creating an opportunity for companies that help folks make the most of their new outdoor living space.

Trex is the top dog in composite decking, giving homeowners an outdoor solution that costs more than traditional wood decking but built to last a lot longer with a lot less maintenance. Trex surprised investors in the second quarter. Wall Street pros were holding out for a year-over-year decline in consolidated net sales, but Trex came through with a 7% gain. Guidance for the quarter that ended two weeks ago calls for sales accelerating to a 13% pace.

Outdoor signage of a Costco Wholesale club on a sunny day.

Image source: Costco.

Costco

Warehouse clubs have not skipped a beat during the pandemic. They remained open when many other retail outlets were closed, and Costco has helped folks stock up on essentials and nonessentials in bulk. Despite some obvious pockets of weakness -- the gasoline pumps outside most Costco locations aren't seeing a lot of action, and the same can be said about the travel bookings they score in kinder times -- Costco as a whole is rocking.

Adjusted comps soared 14.1% in the fiscal fourth quarter it posted last month, capping off a 9.2% gain for all of fiscal 2020. The new fiscal year is off to an even better start. Comps in September clocked in with a 15.5% burst. Costco continues to deliver as the class act among warehouse club operators. 

Freshpet, Trex, and Costco may not seem like high-octane growth stocks, but they're delivering double-digit revenue growth at a time when many historically faster-moving companies are proving mortal. Freshpet, Trex, and Costco earned the new highs they hit last week.