ORLANDO, Florida, Aug 14 (Reuters) - The U.S. economy

seems to be chugging along fairly smoothly, if a little too

slowly for some observers' liking. Under the bonnet, however,

the picture is more worrisome, and the risk of engine

malfunction is rising.

Technology's role in the U.S. economy has never been

greater, and artificial intelligence could deliver a historic

productivity boom. But return on the huge investment being made

on that bet could take years to materialize. What's more, an

unbalanced economy may not be desirable in the long term, as it

can lead to poor investment and policy decisions.

Below are five charts that indicate the foundations of the

resilient U.S. economy and booming stock market may be much

shakier than they appear, especially if AI- and tech-related

spending, investment and optimism are stripped out.

INVESTMENT

Inflation-adjusted investment in 'AI-sensitive' sectors of

the economy since the end of 2019 has risen 53%, notes Troy

Ludtka, senior U.S. economist at SMBC Nikko Securities.

Investment elsewhere has inched up just 0.3%.

CONTRIBUTION TO GDP

Relatedly, the contribution of software and IT equipment

capex to U.S. GDP has never been higher, according to analysts

at BlackRock. Aggregate capex in all other areas of the economy,

however, actually fell in the first half of this year - a rare

occurrence.

CONSUMER SPENDING

Meanwhile, personal consumption expenditures are slowing

sharply, a worrying sign given that the consumer accounts for

around 70% of total U.S. GDP. Personal consumption expenditures

in the second quarter grew by only 0.9%, the slowest pace since

the pandemic. And in real terms, consumer spending has

completely flat-lined in the first half of the year.

CORPORATE BANKRUPTCIES

Corporate bankruptcies in July were the highest for a single

month since July 2020, according to S&P Global Market

Intelligence. Even more alarming, the tally of year-to-date

bankruptcy filings through the end of July was the highest for

this seven-month period since 2010. Nearly a third of this

year's bankruptcies were in the consumer discretionary and

industrial sectors.

STOCK MARKET CONCENTRATION

Finally, the concentration on Wall Street has been widely

discussed, but the levels continue to be eye-popping. One stock,

chipmaker Nvidia, accounts for 8% of the benchmark S&P 500's

entire market cap. That's a record for a single name.

And the top 10 stocks, most of which are Big Tech megacaps,

make up 40% of the index's market cap and 30% of all earnings.

These are also record levels.

The more Wall Street - and even global markets - rely on the

revenue, earnings and profitability of a set of companies that

can be counted on two hands, the bigger the potential mess could

be if the trends driving these companies' performance lose

momentum.

(The opinions expressed here are those of the author, a

columnist for Reuters)

(Editing by Bernadette Baum)