As you know, you can lose a lot of money in lots of ways. You might lose thousands at a casino. Your new car loses a lot of value as soon as you drive away from the dealership. You can lose tens of thousands selling your home if its value hasn't risen since you bought it.

You can also lose a lot by not doing certain things. Fail to buy sufficient home or car insurance, for example, and you could face major expenses. Failing to invest for your future is a major way to lose out on a lot of money. Here's a closer look at this kind of mistake.

Someone is looking at the camera with a serious expression.

Image source: Getty Images.

Investing isn't gambling

Many people aren't investing for their retirement (or any other financial goal) because they're assuming -- incorrectly -- that investing is essentially gambling. Investing and gambling do share some characteristics. For example:

  • With either, you spend a certain sum with the hope or expectation that it will increase in value, potentially significantly.
  • Either can make you significantly wealthier in short order.
  • Both carry risks, depending on the kind of gambling or investing that you're doing.

Despite that, they're two very different activities, with different risk profiles. Yes, a lottery ticket might make you a multimillionaire within a few days -- but it's highly unlikely to do so. And yes, you might invest in a solid blue chip company only to see it fall on hard times and drop in value sharply. But most solid blue chip companies are likely to grow over time. Spread your money across 25 or more companies, and you'll reduce your risk of being hurt by a company unexpectedly imploding.

Or just invest in one or more simple, low-fee, broad-market index funds, such as those that track the S&P 500. Truly, an index fund can be all you need to amass a fat nest egg. Here are a few such funds to consider: the Vanguard S&P 500 ETF (VOO -0.06%) and the SPDR S&P 500 ETF (SPY -0.07%).

Don't procrastinate

Another reason many people aren't saving and investing for retirement is because they're just putting it off. After all, many people don't know enough about the stock market, which can make it easy to just ignore it. If that's you, it's well worth taking some time to learn more about stock investing -- as that's arguably the best way to build wealth over the long term.

How much you can amass -- or leave on the table -- via investing

Now, let's look at a very important table below. It shows how much you can amass if you invest in the stock market regularly over a long time -- and for those not doing so, it shows how much you'd be leaving on the table. Since the stock market (as measured by the S&P 500) has averaged annual returns close to 10% over many decades, the table assumes a more conservative 8% average annual growth rate:

Growing at 8% for

$7,200 invested annually

$12,000 invested annually

5 years

$45,619

$76,032

10 years

$112,648

$187,746

15 years

$211,134

$351,892

20 years

$355,845

$593,076

25 years

$568,472

$947,452

30 years

$880,890

$1,468,150

35 years

$1,339,935

$2,233,226

40 years

$2,014,423

$3,357,372

Calculations by author via Moneychimp.

Note that $7,200 invested annually is $600 per month, on average, and $12,000 is $1,000 per month. Note, too, the huge numbers in the table. If you sock away $1,000 per month for 20 years (a total of $240,000, by the way), you might end up with nearly $600,000 in your investment account. That can be an immensely handy sum at retirement.

But if you could have been investing $1,000 monthly over the past 20 years and didn't do so, that same sum of nearly $600,000 is what you'd have left on the table. Sure, you might have spent that $240,000 on travel and gifts and new cars and maybe a finished basement or big deck for your house, but you'd have a far smaller nest egg to support you in retirement.

Depending on how long you have not been investing and how much you might have invested, you may well have left more than $1 million on the table.

Look forward, not back

Don't kick yourself too much if you're late in starting to invest for your future. You're far from alone, and many people simply don't get a wake-up call about investing until later in life. Here's some good news: You probably still have time to plow lots of dollars into the stock market and build a helpful war chest for retirement.

Even if you're, say, 50, you might work until age 65 or 70, giving you 15 or 20 years of saving and investing. You might also consider postponing your retirement by a few years, because that can be an extremely powerful move.

So don't despair. And don't succumb to procrastination or ignore the stock market because you think it's gambling. Not investing is gambling -- with your future financial security.