The stock market continues to run higher and higher. And while a lot of the big run is the result of U.S. companies having steadily grown their earnings in recent years, plenty of stocks also trade at rich valuations. But there are still some solid values and hidden gems out there if you know where to look. 

Here is a closer look at three stocks that Wall Street may be overlooking, but we think should be on your radar: a surprising growth story in Clean Energy Fuels Corp. (NASDAQ:CLNE), beaten-down multinational utility National Grid plc (ADR) (NYSE:NGG), and the gold and silver miner that's not really a miner, Wheaton Precious Metals Corp. (NYSE:WPM)

Dozens of black arrows pointing to the right, and one arrow pointing to the left.

Image source: Getty Images.

An overlooked growth story

Jason Hall (Clean Energy Fuels Corp.): With a market cap of less than $400 million and a stock price that's fallen over 80% in the past five years, the natural gas for transportation leader is most definitely getting the cold shoulder from Mr. Market right now. The lack of interest has only been exacerbated lately by Tesla's big battery-powered Semi reveal in recent weeks further convincing investors that natural gas doesn't have much of a future in transportation. 

I think that's an overstated claim that's causing investors to miss how strong a position Clean Energy Fuels is in and how much growth it could still have ahead of it. 

To start, electric vehicles are still a lot farther from being viable for the kinds of commercial vehicles Clean Energy's customers use than the headlines make it seem. We are still years away from a viable electric semi, and even when it comes to market, it will have significant limitations on range and the applications it works in. It will also require a significant up-front investment that many fleet operators won't be willing or able to make. 

Natural gas, however, is cheaper today, reduces emissions today, and is available today. That's why Clean Energy has tripled its fuel volume sales since 2010, and continued to grow its volumes by above or near double-digit rates. At the same time, it has lowered expenses, paid down debt, and improved cash flows substantially in recent years

Lastly, around 50 billion gallons of diesel get used on U.S. highways every year, while Clean Energy will sell less than 400 million in 2017. Natural gas (including renewable natural gas, of which Clean Energy is the biggest seller) will likely play a significant role in offsetting that diesel consumption even as electric vehicles start becoming a bigger player. 

Down but not out

Neha Chamaria (National Grid): Down 22% in the past six months, shares of National Grid are now languishing at 52-week lows. Wall Street appears to have gone sour on the U.K.-based electricity and gas utility for two reasons: National Grid sold off a big portion of its U.K. gas distribution business, and foreign currency overhangs in the wake of Brexit continue to weigh on its results. 

First, currency fluctuations are an uncontrollable factor that should dissipate with time. Second, National Grid's portfolio may have shrunk after its gas business sale, but the deal also yielded a hefty profit of $7.5 billion, a major portion of which was passed on to shareholders in the form of a special dividend and share repurchases.

Moreover, despite potential lower revenue from gas, analysts still expect National Grid's earnings to grow roughly 6% each this year and in the next five years. A major factor that could drive earnings is National Grid's focus on the U.S. During the six months ended Sept. 30, 2017, 55% of the 2 billion pounds that the company invested went toward its U.S. regulated business. National Grid pegs its U.S. assets to grow 7% annually in the medium term.

As a utility in the U.S., National Grid can also make rate filings, based on certain criteria, anytime it wants to increase revenue. Higher rates for its Niagara Mohawk utility are expected to be effective from April 2018 even as the company plans to file rate cases for its Massachusetts Gas and Rhode Island Electric and Gas utilities this month. If successful, National Grid's profits could grow at a faster clip.

With National Grid shares now trading at only 14 times forward earnings and yielding a solid 4.9% dividend, it's time to pay attention.

A different kind of precious

Reuben Gregg Brewer (Wheaton Precious Metals): When you hear about silver and gold on Wall Street, people are usually talking about bullion or precious metals miners. But there's another way to get exposure to these commodities: gold and silver streamers like Wheaton Precious Metals.

Streaming companies provide cash up front to miners for the right to buy silver and gold at reduced rates in the future. The model locks in low costs (Wheaton's cost for silver is around $4 an ounce while it pays around $400 an ounce for gold) and wide margins. Since it doesn't actually own or operate mines, however, those margins tend to remain wide in good years and bad for precious metals. Wheaton also has wider diversification than most miners, with 28 investments (20 operating mines and eight in some stage of development).   

The best part, however, is that Wheaton can actually benefit from commodity downturns. That's because miners are usually most desperate for cash when gold and silver markets are in the doldrums. For example, it inked a pair of big deals in 2015 with then-struggling Glencore and Vale SA (NYSE:VALE) that led to record silver and gold sales in 2016 -- right as the commodities had started to turn higher again.   

Silver Wheaton's top line is driven by silver and gold prices, so it can't completely avoid the ups and downs of the commodity market. But for most investors, the streaming model, which is still a lesser-known business approach, is likely to be a better way to invest in precious metals.