Volatile markets cause stress for investors but also create opportunities to buy stocks with solid long-term growth prospects. Of course, it helps if they trade at reasonable valuations, too. With that in mind, investors should take a closer look at security doors and locks company Allegion (ALLE -0.75%), electrical-products maker nVent Electric (NVT -1.38%), and Google owner Alphabet (GOOG 0.37%) (GOOGL 0.35%).

Allegion

There are two main reasons to take advantage of the share-price dip and buy Allegion stock for the long term. First, the company has a long-term growth opportunity due to electro-mechanical convergence in the security industry.

In plain English, doors and locks will no longer simply be mechanical. Instead, they will increasingly be electronically connected and use internet of things (IoT) technology to create more functionality and complexity. Think of a commercial building that can control and monitor which employee has access to which room, and when they were in it. Increased sales of electronic locks, software, and control systems should boost profit margin, too. 

The second reason is the deal to buy Stanley Black & Decker's access technologies (automatic doors and service). The deal completes a gap in Allegion's portfolio and is complementary to its existing offerings in non-residential security. While the acquisition is not exactly cheap -- Allegion's management estimates it's a price of 12.5 times earnings before interest, taxation, depreciation, and amortization (EBITDA) in 2022, assuming tax and synergy benefits -- it does create an additional growth opportunity for Allegion.

Trading at around 19 times management's estimate for free cash flow (FCF) in 2022, Allegion is an attractive stock. Wall Street analysts also expect double-digit earnings growth for the next couple of years.

nVent Electric

The connection and protection products company is a back-door way to play the trend toward electrification in the economy. nVent makes electrical enclosures, electrical and fastening systems, and thermal management solutions for equipment, buildings, and processes. It sells across the industrial, commercial and residential buildings, infrastructure, and energy end markets. There's plenty of growth opportunity in many of these end markets as they increasingly invest in electrification.

Examples include data centers, industrial automation, connected buildings, smart infrastructure, electric-vehicle charging stations, renewable energy, etc. In short, if you're investing in electrification, you'll also need to invest in connection and protection solutions in order to avoid the risk of costly failures and abide by regulatory requirements.

Fortunately, nVent is having a better year than most industrial companies, and management even raised its full-year sales and earnings-growth guidance on its first-quarter earnings call. Trading at 16 times earnings estimates for 2022 and 17 times forecasts for FCF in 2022, nVent remains a good value option for investors looking for a play in electrification.

Alphabet 

The company's management finds itself in an incredibly fortunate position. Google's dominant position in search, YouTube, and Android platforms ensures the company will generate bundles of cash for the foreseeable future. Meanwhile, the torrid growth rates at Google Cloud (revenue up 43% year over year in the second quarter) mean it's simply a matter of time before it turns profitable. 

The amount of cash flow Alphabet generates is astonishing. Wall Street analysts estimate Alphabet will generate $267 billion in FCF over the next three years. It's a figure equivalent to 17.6% of Alphabet's current market cap and enough to buy Boeing, General Electric, and Ford -- and still have more than $50 billion left over in pocket change. 

The implication is that Alphabet's management has a lot of cash, time, money, and options to either return cash to shareholders or invest in businesses to create value for shareholders. Of course, there's no guarantee management will do either of those things, but the pressure will surely build on them to do so. Value investors usually enjoy such situations, and incredible as it may seem, Alphabet's $1.5 trillion market cap represents an undervalued stock.