Shares of RadioShack were in freefall today after sales for the holiday quarter fell 20%. The company is closing more than 1,000 locations, which amounts to more than one-fifth of the company's total stores. Is there any hope at all left for RadioShack, or is this what the death of a company looks like?

In this video from Tuesday's edition of Investor Beat, host Chris Hill and Motley Fool analysts Morgan Housel and Mike Olsen look at the moribund RadioShack. They discuss why niche electronics retailers are being eaten alive in today's retail environment, and why companies such as Best Buy and hhgregg could be next if they don't act fast.

Then the guys look at four stocks making big moves on the market today. Delta Air Lines stock was on the rise today as passenger revenue grew 4% in February, a surprising metric when considering that the company cancelled around 8,000 flights last month. Second-quarter profits for AutoZone were up more than 9%, with same-store sales and gross margins up as well. The retailer was likely boosted by the especially harsh winter, which was tough on vehicles. Plug Power popped by double digits again today, after the hydrogen cell maker announced a deal last week with six Wal-Mart distribution centers. And Tesla Motors announced today that it plans to expand in Europe, with 30 new service centers and stores across the continent.

And finally, Mike and Morgan each pick one stock they'll be watching closely this week, that investors should have on their radar. Morgan tells investors why Paychex stands to benefit from rising interest rates, while Mike looks at Flowers Direct, which operates under the namesake, and tells investors why this is more than just an online flower seller.

Looking for three more great long-term buys in 2014?
It's no secret that investors tend to be impatient with the market, but the best investment strategy is to buy shares in solid businesses and keep them for the long term. In the special free report "3 Stocks That Will Help You Retire Rich," The Motley Fool shares investment ideas and strategies that could help you build wealth for years to come. Click here to grab your free copy today.

Chris Hill owns shares of Michael Olsen, CFA, and Morgan Housel have no position in any stocks mentioned. The Motley Fool recommends and owns shares of, Paychex, and Tesla Motors. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.