Largest Mid-Cap Companies by Market Capitalization

The S&P MidCap 400, managed by S&P Dow Jones Indices, is the most widely followed mid-cap benchmark and tracks 400 mid-sized U.S. companies. It sits within the S&P 1500 family — between the S&P 500 (large-caps) and the S&P 600 (small-caps). The average S&P 400 constituent is roughly one-tenth the size of a typical S&P 500 company and about three times the size of the average S&P 600 member.

There is no single universal definition of mid-cap. The most commonly cited range places mid-cap stocks between $2 billion and $10 billion in market capitalization, though some institutional definitions extend that ceiling considerably higher. Morningstar, for example, uses a percentile-based approach where mid-caps represent the next 20% of total U.S. market capitalization after the top 70% classified as large-cap.

Sector composition sets mid-caps apart from their larger peers:

• Industrials — the largest sector in the S&P MidCap 400, with a weighting nearly triple that of the S&P 500.
• Utilities — carry comparatively heavier weight than in large-cap indices, influenced by infrastructure renewal and energy demand.
• Information Technology — significantly less concentrated than in the S&P 500.

Another key mid-cap benchmark is the Russell Midcap Index, launched in 1991 by FTSE Russell. It measures the 800 smallest companies in the Russell 1000, representing approximately 27% of that index’s total capitalization. Russell reconstitutes its indices annually each June.

Mid-cap companies have generally moved past their earliest growth stages but still have room for expansion. Many eventually transition into the large-cap category, which triggers additional institutional interest. Despite this, mid-caps tend to receive less institutional fund allocation relative to their market representation compared to both large-cap and small-cap stocks.

Several ETFs provide broad mid-cap exposure, including the iShares Core S&P Mid-Cap ETF (IJH), the SPDR S&P MidCap 400 ETF Trust (MDY), the Vanguard Mid-Cap ETF (VO), and the iShares Russell Mid-Cap ETF (IWR). Regulated broker Invest now: Buy Stocks & ETFs in just 15 minutes from $50 Your capital is at risk. Free demo account & education The table below ranks the largest mid-cap publicly traded companies by market capitalization. Companies are classified according to standardized mid-cap criteria (typically $2 billion to $10 billion, though definitions vary). All data — including price and market cap — updates regularly to reflect current market conditions.