Winner-Take-Most Index
This chart tracks how much reported profit, and positive year-over-year profit growth, is captured by the ten largest contributors in SEC XBRL frames, as a four-quarter moving average. Calendar-year filers report the year in a 10-K rather than tagging a standalone fourth quarter, so fourth quarters are rebuilt as the annual figure minus the three reported quarters; implausible reconstructions are rejected and counted in the data file. SEC frames include trusts as well as operating companies, so this is not every business in the economy.
What does it show?
A small group of entities is capturing a growing share of reported profits and profit growth.
Methodology
From SEC XBRL NetIncomeLoss calendar-quarter frames. In each quarter, level share is the ten largest positive net-income facts divided by all positive net-income facts. Growth share compares entities present in the current and year-earlier frames, then divides the ten largest positive increases by all positive increases. Losses do not reduce either denominator; turnarounds can enter growth. A calendar-year filer does not tag a standalone three-month figure for its fourth quarter, because its 10-K reports the year, so the reported Q4 frame holds only off-cycle filers — about 1,100 entities against 5,000 in other quarters, without Alphabet, Bank of America or the other December-year companies. Those quarters are therefore rebuilt: for a calendar-year filer absent from the reported Q4 frame, Q4 is its annual figure minus its three reported quarters, the same reconstruction used elsewhere in this pipeline for income-statement tags. A derived value more than ten times the company’s own other quarters is rejected, because SEC frames carry occasional mis-scaled annual facts and one of those would land directly in a top-ten statistic; roughly 6 to 30 are rejected per year. Rebuilt Q4 frames hold 4,700 to 5,800 filers, in line with the quarters around them, and the per-quarter native, derived and rejected counts are in the JSON audit field. Each plotted point averages four quarterly ratios; a quarter that could not be made comparable would be skipped and named in the audit rather than plotted. Membership still shifts between quarters: a company enters only where it tagged a standalone figure or could be derived, so some filers miss individual quarters. Entity names come from each registrant’s SEC submissions record rather than from the frame, which can carry a co-registrant subsidiary’s name. The published roster is the latest quarter’s level top ten. SEC frames include reporting entities such as trusts as well as operating companies, and coverage is not every U.S. business or filer.