Transportation stocks in the U.S. experienced a sharp decline on Monday morning following an announcement from Amazon.com regarding an expansion of its logistics services. This move positions the e-commerce giant as a major competitor to parcel carriers and air freight companies, while also impacting trucking firms and third-party brokers.

FedEx shares dropped as much as 7.4%, marking their largest single-day decline in over a year. Another competitor, United Parcel Service (UPS), saw its shares fall by up to 8.9%. Logistics companies like Forward Air and GXO Logistics suffered double-digit percentage losses. Several trucking carriers, including Old Dominion Freight Line, declined by more than 5%.

Amazon.com has been developing its distribution network for years, primarily to enhance rapid delivery capabilities for sellers on its own platform. The retail giant is now opening this network to businesses beyond its own marketplace sellers. In a statement issued on Monday, Amazon.com announced it would offer freight, distribution, fulfillment, and parcel shipping services to independent clients such as industrial manufacturer 3M and outdoor retailer Lands' End.

Morgan Stanley analyst Ravi Shanker wrote in a note to clients on Monday that this news "could be a watershed moment for freight carriers in North America." Air freight and parcel delivery companies are likely to be the first affected, while trucking firms, railroad operators, ocean shippers, and warehouse operators also face risks.

Amazon.com operates an extensive network of warehouses and delivery stations, mainly used for fulfilling and delivering customer orders. The company is now seeking to utilize excess capacity within its network by offering transportation services to external parties, even for shipments unrelated to its core e-commerce business. This strategy expands the total addressable market for Amazon.com while simultaneously posing a threat to the operations of UPS and FedEx.

"Amazon.com has been moving in this direction for years, offering parts of its supply chain capabilities as a service to non-Amazon sellers," said Nate Skiver, founder of shipping consultancy LPF Spend Management. "Bringing an end-to-end capability to market as a unified service has the potential to be disruptive to the U.S. logistics landscape."