Rural Telecom Flickr User Chas Redmond
Telecom stocks were weak today. Image: Chas Redmond via Flickr.

The stock market behaved badly on Wednesday, reversing course after two days of gains. Market participants attributed the losses to pressure in the energy market and weakness among some of the largest companies in the U.S. economy, with major-market benchmarks falling between 0.5% and 1% on the day. Some stocks got hit particularly hard, with Sprint (NYSE:S), Windstream (NASDAQ:WIN), and Vanguard Natural Resources (NASDAQ:VNR) among the biggest losers in the session.

Sprint fell 6% as the mobile carrier continues to navigate an increasingly competitive mobile-service market. In recent weeks, players in the industry have ratcheted up their offers to customers of competing services, with Verizon having announced earlier this week that it would pay as much as $650 to cover any termination fees that Sprint and other carriers would charge. As lucrative as the mobile revolution has been for many players in the industry, Sprint and its rivals are now engaged in a difficult price war that could threaten future profits if current trends toward greater incentives for switching continue.

Windstream was also down 6%. The telecom company has continued its efforts to expand its service in order to compete with larger players like Sprint and Verizon, looking to expand enterprise solutions for business customers while urging its residential customers to adopt higher-margin broadband access in lieu of hanging on to antiquated landline services. Yet Windstream is also vulnerable to moves from mobile carriers to lure subscribers away, as many people have decided that forgoing traditional telecom service is now an option. Today's drop left Windstream shares down significantly from earlier in the year, and investors appear to fear that a rising-rate environment could further dampen interest in the telecom industry going forward.

Finally, Vanguard Natural Resources dropped 13% on a bad day for the energy industry. Analysts at Morgan Stanley singled out Vanguard for a downgrade, citing lower earnings forecasts that are resulting from falling expectations among energy traders for a substantial rebound in crude oil and natural gas prices in 2016. Oil prices fell back on Wednesday after seeing gains earlier in the week, and supply and demand for energy products has moved further out of balance as it becomes apparent that a near-term resolution to the current glut is unlikely. Even though Vanguard Natural Resources and its peers in the oil and gas industry have already suffered dramatic losses, there could be even more trouble in the future if the energy market isn't able to stabilize and show signs of moving back upward in the months to come.

Dan Caplinger has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.