When the stock market goes on a nice run like it has lately, some investors start to second-guess themselves. "Should I wait for prices to fall, or go all in? Are things getting overheated, or just getting started?"

In reality, no one can answer that question with 100% certainty. The best way to deal with that is to discipline yourself to follow a regular schedule of investing.

That's where our Rising Stars come in, offering up their best investing ideas on a regular basis, whether the market is up, down, or sideways. Add these companies to your watchlist, and you'll be up to date on all the current news. At the end, I'll even offer access to a special free report highlighting three U.S. companies that are set to dominate the world!

Zipcar (Nasdaq: ZIP)
Rising Star Alyce Lomax and her brand of socially responsible investing is more than just a feel-good story: She's the top performer among all Rising Star analysts, beating the market by 8 percentage points as of Jan. 19.

The green aspects to this business are pretty obvious. Reducing the number of cars on the roads, as well as forcing drivers to be more intentional about their driving habits, will undoubtedly reduce carbon emissions. And a recent partnership with Ford (NYSE: F), which will be providing cars with the guarantee of repurchase, doesn't hurt either.

But the story goes beyond that for Alyce: "Zipcar estimates that its members save an average $500 per month compared to car owners. Regardless of the green factor, many urbanite consumers could catch on that this method of only accessing a car when it's truly necessary could save them some serious cash."

LinkedIn (NYSE: LNKD)
Rising Star Dave Meier thinks this company is perfect for his Trends and Trades portfolio. This social networking site is often grouped with other dot-com startups as having questionable revenue streams reliant upon advertising.

But with LinkedIn, that's a false assumption. Check out its three lines of business and the growth rates that each is showing.

Segment

Revenue

% of Total

Growth

Hiring solutions $71 million 51% 160%
Marketing solutions $40 million 29% 113%
Premium subscriptions $28 million 20% 81%

Source: Company's conference call.

Dave thinks the possibilities are endless, comparing LinkedIn to an earlier version of then-misunderstood Amazon.com. In his words:

Many investors saw Amazon.com merely as an online bookstore. What Amazon.com really wanted to be was the greatest online retailing platform, able to sell whatever it wanted. LinkedIn wants to be the quintessential professional network, where people can not only find new jobs, but also find ways to be more productive and successful in their current ones.

GameStop (NYSE: GME)
Rising Star Jim Mueller has built his portfolio around companies with stock prices that show the market's unreasonable distaste for them.

Sometimes it takes awhile for his bets to pay off, but when they do, he's handsomely rewarded. Just consider his double-dipping buys of Dendreon (Nasdaq: DNDN), a pharmaceutical company that's recently seen its fortunes improve on the basis of its prostate drug Provenge. Though the stock didn't do too much for Jim in 2011, it's up 94% for him in 2012!

He thinks the same could happen with GameStop, a company that analysts have written off as a dying bricks-and-mortar retailer. But Jim says the company is refusing to die, taking three solid steps to solidify its future.

  1. GameStop's PowerUp Rewards program is catching on with customers, growing from 4.5 million members to 15.5 million in just a year's time.
  2. The company is strengthening its digital business with Impulse (a downloading site), Kongregate (a casual gaming site), and Spawn Labs (a cloud gaming subsidiary).
  3. It is working with content providers and console providers to strengthen these digital channels.

More motley ideas
Our Rising Stars are a starting point for your investing endeavors. But they are by no means an ending point. Our top analysts have put together a special free report on three companies set to dominate the world. I suggest you continue your investing journey by grabbing a copy of this report today, absolutely free!