The market is taking a breather this week.

With the major indexes now down over 1% in December, it’s a good time to look at where the next big opportunities will be in the market.

Much attention is being paid to the age of the bull market. All speculation seems to be on when this run will end.

That should be viewed as good news because bull markets tend to end with blow-off rallies, rallies that surprise even the most optimistic of pundits.

If indeed the bull market does end, I’d bet big money that the biggest gains will come from the small-cap space where those stocks have lagged in 2014.

If you don’t mind the risk that comes with such a strategy you could be poised for double-digit gains quite easily in 2015.

Stop worrying about valuations, the economy or geopolitics. Instead, take the plunge and find yourself some intriguing small-cap stocks that trade for less than $10 per share.

A good starting point for your search is Wall Street analysts.

Some of the highest-rated small-cap stocks under $10 per share are likely to have the buying support of the big Wall Street firms thats needed to push shares higher.

For example Merrill Lynch upgraded the online coupon company, Groupon (NASDAQ: GRPN), to buy from neutral.

Technically, Groupon is not a small-cap stock with its market cap above $4 billion, but at $7 per share the stock doesn’t have to move much to make big money.

Merrill put a price target on the stock of $9.50 per share. Hitting that number would represent a nice 30% gain from current levels; given the growth in the economy and importance of online retail, Groupon will likely reach that target at some point in 2015.

Questions about the global economy have resulted in the collapse of small-cap shipper Star Bulk Carriers (NASDAQ: SBLK). but often such a sharp drop in share price creates opportunity.

That is certainly the case with Star Bulk.

Last week the company released earnings results that beat expectations. That should stem the tide and stabilize the share price.

Looking forward, Wall Street sees a big opportunity here.

Stifel Financial kept a buy rating on the stock and slightly reduced its very optimistic price target to $14 per share from $16 per share.

The average analyst target for Star Bulk is just under that $14 at $13.83 per share, which would represent a near-100% gain in share price.

To the extent central banks across the globe are successful reigniting economic growth, Star Bulk is going to be a big winner.

The collapse in oil prices have crushed stocks in the alternative energy space like FuelCell Energy (NASDAQ: FCEL) .

FuelCell shares have collapsed since hitting nearly $4 per share earlier this year.

Sidoti & Co. upgraded the stock to buy from hold last week as one of many calls that a bottom in crude is near.

To the extent that is true, FuelCell shares could easily double in value once the market realizes that alternative energy is still important even with crude oil prices at the currently low prices.

I wouldn’t go all-in on stocks under $10, but adding a few like the above could turbo-charge your portfolio next year.