(Bloomberg) -- As higher egg prices add to inflation for US consumers, producer shares are providing investors with outsized returns.

Shares of the top US egg supplier Cal-Maine Foods Inc. have more than doubled over the past year, gaining 127% in the period to hit record levels on Thursday. Smaller rival egg company Vital Farms Inc. has surged 152%. The companies have outperformed all major animal protein suppliers including Tyson Foods Inc., Pilgrim’s Pride Corp. and JBS SA.

Egg supplies have been constrained by a bird flu outbreak, and higher prices for the food helped to drive an unexpected acceleration for US wholesale inflation in November. The producer price index on Thursday showed egg prices surged 55% from a month earlier.

Cal-Maine, which produces roughly one in every 10 eggs supplied in the US, has become a bellwether for the market. Suppliers are getting paid the most on record for the protein-rich ingredient at this time of the year. Farmers have culled millions of egg-laying hens and pullets to stop the spread of a highly pathogenic avian influenza, keeping a lid on output.

“What you’re seeing is a company that has massive scale that is reaping the benefits of strong price leverage,” said Pooran Sharma, an analyst at Stephens Inc., citing the impact on bird flu on supplies. “We’re in a super cycle right now.”

The egg market has stood out for its disrupted production since the depths of the pandemic. Years of dealing with supply-chains snarls and poultry disease have kept output limited and retail prices elevated. Consumers have also been frustratingly faced with empty grocery shelves during temporary supply shortages.

Earlier this week, the US Department of Agriculture said domestic production this year and in 2025 will be smaller than previously expected, further underpinning prices.

Eggs are still one of the more affordable sources of animal protein and can’t be easily replaced in cooking, meaning demand tends to be resilient even when prices rise.