Bitcoin counts as an investment only if you're an absolute adrenaline junkie. Coin prices moved from $960 to $19,000 last year, only to crash back down below the $7,000 mark again. 

For investors who prefer their high-growth plays to be backed by actual business results, there are many lower-risk alternatives on today's stock market. To help you strike that delicate balance between exciting growth prospects and reasonable market risks, we asked a handful of your fellow investors here at The Motley Fool to share their best high-growth ideas not named bitcoin. Read on to see why they recommend Microsoft (MSFT 0.74%)Coscto Wholesale (COST 1.68%), and Micron Technologies (MU 2.55%) at the moment.

Businessman scratching his head in front of a chart showing downward arrows and a large bitcoin logo.

Don't let bitcoin keep you up at night. Image source: Getty Images.

Bulk up on predictable returns

Demitri Kalogeropoulos (Costco): One of the biggest risks of investing in bitcoin is all the uncertainty about the cryptocurrency's long-term value. Why not consider a stock like Costco, which has a far steadier runway for growth?

The warehouse retailing giant has a simple business model. Its efficient operating approach makes it a cost leader, and with help from its membership fees, that advantage allows it earn profits while selling products at rock-bottom prices. It's a proven model that tends to deliver market-thumping results. Sales are up a blistering 7% over the last six months even as higher subscription fees helped net income spike 27%. 

Like its retailing peers, Costco is busy trying to strike the right balance between making full use of its physical store footprint and expanding the e-commerce sales channel. Its loyal shopper base -- over 90% of subscribers re-up each year -- suggests it is succeeding in that goal. 

Since most of its earnings come from those membership fees, the retailer's profits are far less volatile than those of its peers. The path for future growth is clear, too. As long as Costco keeps delighting customers and expanding its membership base, it's likely that its sales base, and earnings power, will be much stronger ten years from now.

If memory serves, this stock is spring-loaded right now

Anders Bylund (Micron Technology): You're looking for explosive growth, right? Here's a stock that has gained 77% over the last 52 weeks, and it still looks cheaper than dirt.

Memory chip maker Micron Technology offers exactly that tempting combination. You get the best of several worlds, from proven success and solid profits to exciting sales growth and undervalued shares.

In a memory market that has been haunted by cyclicality and brutal price wars, Micron has enjoyed predictable supply and-demand conditions and stable product prices for a couple of years now. Annual revenues have doubled in two years, taking Micron's free cash flows from negative territory to $7.1 billion of black ink. Over that period, share prices have nearly quintupled. Not quite a bitcoin-style gain, but it's a downright adrenaline-packed growth story by Wall Street's standards.

Market makers can hardly believe Micron's improving finances. The stock is valued for absolute disaster, as if the next price war is just around the corner. You can pick up Micron stock at rock-bottom rations like 5.6 times trailing earnings, or 8.2 times free cash flows.

And the thing is, the next price war is almost certainly not coming 'round the mountain right now. In fact, heavy consolidation followed the last couple of downturns, and Micron is now one of a mere handful of memory chip suppliers on a global level. Flooding the market with chips to drive unit prices way down makes almost no sense under these conditions, and all of the major names look ready to settle down in a mature market model for the long run.

So do yourself a favor. Pick up some Micron stock instead of those hyper-volatile cryptocurrencies. This investment can make you rich without making you spend it all on antacids and sleeping pills.

The blockchain underdog

Leo Sun (Microsoft): Instead of buying bitcoin, investors should focus on blockchain, the distributed ledger technology that powers most cryptocurrency transactions. Outside the crypto market, blockchain can be used to validate transactions for financial institutions, logistics providers, food suppliers, and other industries.

IBM (IBM 0.13%) is the market leader in blockchain technologies, but its core business is filled with legacy operations offsetting the higher growth of its cloud, mobile, analytics, security, and social businesses. As a result, analysts expect IBM's revenue and earnings to only rise about 1% this year.

A more balanced play is Microsoft, which ranks second in the blockchain race. Last year, a Juniper Research survey found that 20% of tech leaders ranked Microsoft as the blockchain market leader, compared to 40% for IBM. But over the past year, Microsoft invested heavily in expanding its blockchain capabilities on its cloud platform, Azure, and leveraging the technology to protect users' digital identities.

Blockchain remains a tiny part of Microsoft's business, which relies more on the growth of its cloud services than sales of enterprise software. But unlike IBM, Microsoft isn't stuck in neutral. Wall Street expects its revenue and earnings to both rise 11% this year, fueled by the growth of cloud services like Azure and Office 365, and the expansion of its "One Windows" ecosystem across the PC and console markets.

Microsoft isn't cheap, at 26 times this year's earnings, but it's a well-rounded tech play that will benefit from the growing adoption of blockchain networks.