Market-cap sizes (large, mid, small).
In plain English
Market cap, share price times shares outstanding, sorts every public company into one of three rough size buckets. The thresholds are convention used by Wall Street and the major index providers, not legal definitions. Large-cap names are typically household-recognized with stable revenue. Mid-cap names are mature businesses still in growth phase. Small-cap names are smaller, less liquid, and often more volatile.
01Why it matters
Size correlates loosely with risk and return. Small-caps have historically delivered higher long-run returns and higher volatility than large-caps. A diversified portfolio typically holds exposure to all three. Many total-market index funds already provide this; an S&P 500 fund alone leans heavily large-cap.
02The math, step by step
Large-cap example. Apple's market cap in 2026 is roughly $3.5 trillion, far above the $10 billion threshold. Microsoft, Nvidia, Amazon, Alphabet, Meta, and Berkshire Hathaway are all large-cap. Mid-cap example. A regional bank like Pinnacle Financial Partners with market cap around $7 billion sits in the mid-cap band. Small-cap example. A specialty retailer trading at $1.4 billion market cap is small-cap. The Russell 2000 is the standard small-cap index.
03What this is NOT
Market cap is the equity market's valuation of the company, not the company's revenue. A high-margin tech company can have huge market cap on relatively small revenue. A low-margin retailer can have substantial revenue on smaller market cap.
04Receipts
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