I'm pretty happy with how my retirement savings are stacking up so far. But if I had known then what I know now, I would have done a few things differently in the beginning.

With that as the backdrop, here's what my retirement portfolio would look like if I was just getting started with $50,000 in cash and had several years before I would need this money. Note that there's a sizable piece of this stash I wouldn't do anything with just yet, knowing there will be compelling prospects popping up in the future that I'll want to step into without selling any of my existing holdings.

Start with an S&P 500 index fund

Amount: $15,000

Yes, I practice what I preach about indexing. That's why the biggest single holding of any new blank-slate portfolio would be generalized exposure to the broad market with a position in the SPDR S&P 500 ETF Trust (SPY -0.66%).

Some people consider it the chicken's way out of picking individual stocks. Indeed, given that the market's been the focal point of my profession since I entered the industry as a broker way back in the 90s, plenty of people seem genuinely surprised I'm not more of a stock speculator now.

The thing is, after 20+ years of being in the business, I've evolved into a firm believer in the idea that less is more, and simpler is better. I also don't have time at this stage in my life to devote to managing a large number of holdings, yet I still have faith that stocks as a whole can do plenty of heavy lifting for me.

3 well-built growth stocks

Amount: $5,000 each

Although an index fund may be my chosen centerpiece of a brand new retirement portfolio, I won't pretend I haven't been bitten by the stock-picking bug. My only qualification for owning individual growth companies is that they'll be in a position to perform five, ten, and even twenty years down the road as well as they're performing now.

This standard eliminates a lot of companies! In fact, I contend it leaves behind only a handful of truly great growth stocks.

One of these names is Microsoft (MSFT -0.74%). Yes, shares of the software giant are down by nearly a third from their late-2021 peak, largely on fears of an economic slowdown. The company's recent decision to lay off 10,000 workers as part of an even bigger cost-cutting effort validates the sell-off's underlying drivers. I'm not really worried though. The stock's pullback is an opportunity to plug into a company that's at the very heart of how you interface with the digital world, at home, at work, and in some case even via your phone. As long as you and your employer intend to use technology, you'll need Microsoft to help make it happen.

In a similar sense, Nvidia's (NVDA -2.61%) big pullback from its late-2021 high may have made short-term sense, but ultimately serves as a long-term buying opportunity. The company's hardware is powering the majority of the planet's artificial intelligence platforms these days, and market research outfit IDC estimates global spending on AI systems will grow at an annual pace of 26.5% through 2026.

I'm rounding out my list of three top growth names with Visa (V -1.37%). Were it just the credit card middleman it was a couple of decades ago, I might pass this name by. That's not what today's Visa is, however. It's evolved into a full-blown innovative fintech outfit, responding to cultural changes in how consumers and corporations spend their money. As long as money is around, Visa will enjoy lots of opportunity.

Seeking out safety and reliability

Amount: $5,000 each

There are only two less growthy, safer companies I see as worth taking on as long-term trades right now. One of them is Walmart (WMT -0.10%). The other is Merck (MRK 1.22%).

With just a superficial glance it would be easy to assume Walmart's got little room left to grow. It's already the United States' biggest brick-and-mortar retailer by far, managing more than 5300 Walmart and Sam's Club stores in the U.S. alone. Where else can it put them? In the meantime, Amazon's grip on the domestic e-commerce market looks unbreakable. Insider Intelligence's eMarketer reports Walmart.com only accounts for about 7% of the country's online shopping, versus Amazon's 41%.

Don't count Walmart out just yet, though. It's slowly but surely adding e-commerce market share, up from just 4% of the U.S. market as recently as 2018. And it's evolving in a way that makes the retailer more of a lifestyle choice and less of a mere seller of basic goods. Healthcare clinics, private-label premium wines, and subscription-based delivery service Walmart+ are all examples of the retailer's efforts to earn and keep consumers close. None of these initiatives are immediate game-changers, but collectively they're chipping away at competitors.

As for Merck, the drug company's bullish thesis is even simpler. The world's never going to not need medicine, and Merck's got the size, cash, pedigree, and proven history to continue developing and acquiring the new drugs that assure future revenue.

It's also worth adding that the next several years could be ones that favor value stocks like Merck and Walmart over the average growth name. Growth stocks' leadership since the dot-com crash of 2000 has a lot to do with ultra-low interest rates that were finally pushed up in a big way last year. It wouldn't be crazy to skip one of the aforementioned growth stocks and instead add a value name you like to the mix.

Saving some for later

Amount: $10,000

As was noted, I'm not in any particular rush to invest every single penny of the hypothetical $50,000 I've got at my disposal right now. I'm going to keep 20% of this stash liquid, ready to deploy when the right opportunity arises in the future. That's probably a little more cash than true long-termers might normally want to keep on hand. But you get the point -- the last thing you want to be forced into doing is selling a stock at an inopportune time just to free up capital for a new pick that wasn't on your radar.