The Nasdaq Composite fell about 1% on Monday.

That followed Friday's drop and a rough October.

If you own AI-linked tech stocks, it may have felt like more of the same.

We invest our own savings and retirement money right alongside yours.

But across the S&P 500's large-, mid-, and small-cap indexes, more than twice as many stocks rose as fell.

So far, the selling has hit one corner of the market.

In his October Quarterly Call, Motley Fool co-founder and CEO Tom Gardner pushed back on the idea that big, sudden moves show the most conviction.

"I would argue that the best form of conviction is the step-by-step incremental moves where you have to rethink your thesis as you buy a stock or rethink your reasons for selling a stock in your portfolio," he said.

That takes discipline when prices swing.

Below, we share two habits that can help.

But first, a reminder...

Tech Fell, Most Stocks Didn't Monday's tech selling had familiar roots.

Oracle (ORCL +6.42%) fell almost 9% after filing to raise $20 billion in stock and debt for its AI build-out.

Marvell Technology (MRVL +0.34%) agreed to buy Lumentum (LITE -0.09%) in a $115 billion all-stock deal.

Marvell shares dropped about 13%, and Lumentum fell nearly 19%.

Both moves revived last week's doubts about whether all that AI spending will pay for itself.

The Nasdaq-100 fell 1.4%, and the technology sector lost nearly 3%.

Energy fell about 4% as oil dropped more than 7% on signs of U.S.-Iran diplomacy.

Almost everywhere else, the day looked good.

The Dow rose 0.4%, and eight of the 11 S&P 500 sectors gained.

Only three fell: energy, technology, and healthcare, which slipped just 0.15%.

Across the S&P 500, MidCap 400, SmallCap 600, and Nasdaq-100, 1,027 stocks rose, while 473 fell.

The regular S&P 500, which gives the biggest companies the most weight, fell 0.5%.

An equal-weight version, which counts each company the same, rose 0.8%.

So the typical company had a good day, and a handful of giants dragged the headline number down.

As we noted Friday, 10 companies make up 39% of the S&P 500's value.

Their moves can swamp what the other 490 are doing.

Tech's pullback may not be over.

But if you own a diversified portfolio, most of your stocks probably had a perfectly fine Monday.

When you own businesses across many industries, gains in some can offset a rough day in others, as they did on Monday.

When we launched our 50-stock Epic Portfolio in April, TMF Chief Investment Officer Andy Cross put it this way: "Fifty stocks provide....