How Many of the Largest Companies Do You Own -- and Should You Own More or Fewer?

More than a dozen companies these days have values topping $1 trillion.

You might want to own a range of companies of different sizes.

One noteworthy event in 2018 was that the tech company Apple became the first to reach a trillion-dollar market capitalization .

Today, there are more than a dozen such companies. Here are the recent top 10 largest companies by market cap . See how many of them you own.

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If you own any stocks or funds, there's a good chance you own at least a few of the sizable businesses above. Nearly all of the above companies, for example, are present in S&P 500 index funds , such as the Vanguard S&P 500 ETF (NYSEMKT: VOO) . Most are also in growth-oriented mutual funds or exchange-traded funds.

Looking at the table above, it's hard to argue that you shouldn't invest in large companies. After all, the ones with valuations of $3 trillion, $4 trillion, or $5 trillion were still large some years ago, with valuations of $1 trillion or $2 trillion. These massive companies have these massive valuations because they have executed their plans well and have grown their operations at a good clip.

There are pros and cons to both large- and small-company investing, though, of course. For example: