The Russell 2000 index, which tracks small- and mid-cap stocks, has <a href="https://finance.yahoo.com/quote/%5ERUT/">risen</a>&nbsp;5% over the last month and could soon <a href="https://www.barrons.com/articles/small-cap-stocks-rally-russell-2000-88aac4b9?refsec=small-caps&amp;mod=topics_small-caps">surpass</a>&nbsp;its 2021 record. Some Wall Street strategists <a href="https://www.bloomberg.com/news/articles/2025-09-12/wall-street-expects-rally-in-riskiest-stocks-to-last-12-months?embedded-checkout=true">believe</a>&nbsp;the rally is just beginning, while others <a href="https://www.barrons.com/articles/small-cap-stocks-rally-russell-2000-88aac4b9?refsec=small-caps&amp;mod=topics_small-caps">argue</a>&nbsp;these companies may struggle to sustain momentum amid a sluggish economy.

Russell 2000 nears record high: How long can the small-cap rally last?

KLA Corporation

MercadoLibre, Inc.

Taiwan Semiconductor Manufacturing Company Limited

Cadence Design Systems, Inc.

AI is the one "big idea" worth betting on, argues Janus Henderson Global Technology and Innovation fund manager Danny Fish

The head of an IT stock fund that far outperformed the S&amp;P 500 named four favorite companies

Robinhood Markets, Inc.

AppLovin Corporation

EMCOR Group, Inc.

MarketAxess Holdings, Caesars Entertainment and Enphase Energy will leave the index

AppLovin and Robinhood will enter the S&amp;P 500. Their shares jumped

Broadcom Inc.

Alphabet Inc.

The three major U.S. stock indices moved sharply to the downside after hitting new records at the start of trading on September 5. After the opening of the stock exchanges, investors' optimism was linked to the prospects of Fed rate cuts amid weak employment data for August. However, as the trading session progressed, these hopes were replaced by concerns about a slowdown in the US economy and a possible recession.

The main US indices went from rising to falling after the record. What are investors afraid of?

Labor market data for August was about three times lower than expected

U.S. stocks hit a record after the jobs data. The market is waiting for three rate cuts

Chart Industries, Inc.

Lumen Technologies, Inc.

Badger Meter, Inc.

The second quarter opened with a rout after U.S. President Donald Trump announced his tariff plan on April 3, with tariffs to be raised several dozen percentage points. The S&amp;P 500&nbsp;<a href="https://www.reuters.com/markets/sp-500-loses-24-trillion-market-value-biggest-one-day-loss-since-2020-2025-04-03/#:~:text=April%203%20(Reuters)%20%2D%20S%26P,tailspin%20on%20March%2016%2C%202020.">erased</a>&nbsp;$2.4 trillion in value in a single day, the steepest one-day loss since the pandemic. Small-cap stocks were hit harder by the selloff. Between April 2 and April 8, the small- and mid-cap Russell 2000 plunged 14%, versus a 12% decline in the large-cap S&amp;P 500.

Freedom Finance Global: Hedge funds trim health care, add to cyclicals and tech in 2Q

Investors may have been encouraged by the court's ruling in the antitrust case against Google

U.S. stocks resume gains after a poor start to the fall

NVIDIA Corporation

Meta Platforms, Inc.

Microsoft Corporation

Evercore sees the short-term pullback in the U.S. stock market as a lucrative buying opportunity

S&amp;P 500 could reach 9,000 points before AI bubble bursts - Evercore ISI

Amazon.com, Inc.

Uncertainty over duties and rising bond yields spoiled investor sentiment  

'Wake up when September is over': U.S. stocks have started fall with a dip 

Morgan Stanley's Michael Wilson suggests buying back U.S. stocks on drawdowns that may occur amid seasonal weakness on Wall Street

Morgan Stanley strategist, who guessed the dynamics of shares in spring, bets on the continuation of the rally

The bank advises to bring the share of bonds in the portfolio to 40%

Wells Fargo recommends rethinking portfolio structure: volatility ahead

Aeva Technologies, Inc.

Applied Digital Corporation

Pagaya Technologies Ltd.

The excitement around artificial intelligence is heating up not only the securities of technology giants. Against the background of record quarterly reports of Big Tech and growing optimism of Wall Street, investors are finding undervalued ideas in the small capitalization segment. The biggest gainers are companies creating infrastructure for AI development - from building data centers to supplying specialized equipment and solutions.