It is now easier than ever to invest with small sums of money. That's good news for investors, particularly if you like high-priced stocks. Ordinarily, you would have to shell out the entire stock price since you couldn't buy a portion of a share. If that was too steep, you could hope the company would conduct a stock split that would lower the price.

That's changed, helping small investors. Several brokerage houses, such as Fidelity Investments, Charles Schwab (SCHW -0.10%), and Robinhood Markets (HOOD 6.60%) offer customers the ability to buy fractional shares, which are portions of a company stock, rather than a full share.

Better still, those companies, and others, offer commission-free trades. That means you shouldn't have to shell out extra money to the brokerages to buy and sell stocks, making it even more compelling for small investors.

More investment opportunities can leave you feeling overwhelmed at times, however. While you have more choices, you still have to make wise decisions. To help you get started, here are two strong companies to consider.

An adult giving a child spare change to put in her piggy bank.

Image source: Getty Images.

Everyone's favorite online retailer

With Amazon's (AMZN -0.17%) nearly $3,300 share price no longer an impediment thanks to fractional shares, you can turn to the company's fundamentals. Fortunately for investors, the story seems to remain sound.

While Amazon started as an online bookseller, it quickly evolved into a marketplace where you can find just about anything at a competitive price. It has expanded its reach with offerings like Alexa, and there's the company's ever-popular Amazon Prime subscription service that provides ultra-fast delivery.

When Amazon expands into these areas, it typically dominates the field while changing the industry's dynamics. You can see the "Amazon effect" in sectors such as food and apparel. In those industries, Amazon's low prices and convenient delivery have upended the sectors. For example, in the case of apparel, Amazon allows consumers to easily return the items, allowing shoppers to avoid long lines and fitting rooms.

It doesn't just enter markets to build sales, though. The days when it wasn't profitable are long gone. In the first half of the year, Amazon's sales have grown by about 35% to $221.6 billion. Over that span, the profit more than doubled to $15.9 billion.

Amazon is more than an online retailer, too. It also has a significant cloud-computing business. Although this segment is the company's smallest sales generator, the fast-growing division saw its top line rise by 35% to $28.3 billion. It's also Amazon's largest profit generator with $8.4 billion of operating income.

Beyond search

Alphabet (GOOG 0.72%) (GOOGL 0.83%) has two classes of shares, and each sells for about $2,700. It's better known by its major subsidiary Google, which produces almost all of its revenue and Alphabet's entire profit. Owning a piece of this company, even less than one share, is worth considering.

Alphabet is much more than a search engine, though. It generates a ton of advertising revenue from other sources, such as Google Maps and YouTube. Then there's its "other bets" segment, which takes high risks in the hopes of high rewards. This division typically includes earlier-stage technologies that don't relate to its core Google services. Some companies it invests in don't have revenue yet. All of its businesses together add up to a huge amount of revenue and profit.

In the first half of the year, Alphabet's revenue grew by more than 47% to $117.2 billion. This drove profits 164% higher to $36.5 billion.

Management isn't resting on its laurels, either. It is pushing ahead with initiatives such as artificial intelligence and Google Cloud, and with its enormous audience, Alphabet's revenue and profitability engine doesn't look set to stop anytime soon.

Previously, these two businesses would've been out of reach for small investors. That's no longer the case, although I suggest checking that your brokerage doesn't charge commissions and making sure it offers fractional shares on a wide range of stocks. Finding one that does both isn't too hard these days.

While the initial cost is low, you can keep investing small amounts. If you still like Amazon and Alphabet's prospects, you may consider investing the same amounts at regular intervals, a process called dollar-cost averaging. Before you know it, you could own a good amount of these two businesses.