Dados B3 › What we do not fix · Português

What Dados B3 does not fix: 401 companies left the register since 2010 and none of them is in the base

Every data source has holes. The difference is who measures them. This page exists because a public comparison of Brazilian market data sources claimed that Dados B3 “keeps the history of closed and delisted companies” — the opposite of what we do. The error favoured us, which is the worst kind: anyone choosing us because of it would build a biased backtest believing it was clean.

The size of the hole

The universe comes from the regulator's register with one filter: only companies whose status is ACTIVE. That is 455 companies. Outside them the register carries 1,904 non-active records, and 401 are Category A companies — those required to file full statements — that cancelled registration from 2010 onwards. The intersection between the two sets is 0: not one of them is in the base.

Who disappears, and why it matters

The ones that leave are not a random draw. Out go those acquired, those that went private, and those that failed — and it is the third that ruins a backtest, because the bad return is exactly what disappears. The six most recent, from the register itself:

CompanyCancelled
T4F Entretenimento Sa2026-09-01
Neogrid Participacões S.A.2026-07-14
Massa Falida De Tecnosolo Engenharia Sa2026-06-10
Blue Tech Solutions Eqi S.A.2026-06-10
Tekno S.A. Indústria E Comércio2026-05-14
Pet Center Comércio E Participações S.A.2026-05-14

Cancellations per year

YearCompanies
202615
202520
202420
202317
202222
202119
202011
201923

Why we do not fix it

Fixing it would require the historical series of the cancelled companies, which the regulator does not publish in usable form: each year's file carries whoever was required to report that year, and rebuilding the eligible universe for every date is work we have not done. Measuring and publishing is what can be done honestly. Promising the rest would repeat the very error this page corrects.

The other limits, said plainly

The historical universe is not reconstructed

The base holds the companies that are active today. A backtest run over 2015 with it is picking among the firms that made it to 2026 — information nobody had in 2015. That inflates returns, and inflates them more the longer the window.

Delisting is not an event we represent

There is no exit date, no final price, no return through the close. A company simply stops appearing. Anyone needing the return of a position up to the delisting will not find it here.

Historical index composition does not exist here

We do not know who was in the main index in 2013. Our sector index is built from the regulator's sector classification over the current universe: it compares sectors against each other, it does not reproduce an index portfolio.

The series starts in 2010

That is when Brazilian accounting converged to IFRS. Before it the chart of accounts is a different one, and stitching the two eras together would produce a series continuous in appearance and incomparable in substance.

what we DO fix: the look-ahead from price and filing · transparency · comparison

Numbers on this page are live. Data version 2026-09-01-supressao-declarada · page generated 2026-09-08 11:13 UTC. If this does not match /saude, you are reading a cached copy.

Home · Methodology · Transparency · Audit it