Market data travels through a chain of providers and breaks where nobody looks: the share count after a merger, oil companies' capex, out-of-scale earnings, incomplete debt. The real cases found across 3,500 US companies and what we do every night so as not to show them broken.

Fundamental analysis has solid foundations, but works differently from what people think: a small edge on groups of companies, not a forecast for a single stock. Verified studies, the limits on market timing and sizing, and our measure on 2,900 US companies.

The S&P 500, the whole US market, the world and small caps: what they contain, what they cost according to MSCI, what research says about passive funds and our measure on 3,200 US companies.

Artificial intelligence, clean energy, uranium: the research and our measure on 140 US thematic ETFs compared with the 11 S&P 500 sectors, on returns, declines and closures.

Microcaps, hyped stocks, class actions: thirty years of research on what retail investors really do, who weighs more on the market's scale, and our measure on 2,359 US stocks.

Manuals teach how to read charts, but rarely say how often a signal worked. Thirty years of research, what holds up, what does not, and our measure on 3,038 stocks.

The 4% rule lasted 30 years in 119 retirements out of 123 since 1871, with 60% in stocks. When it fails, how much the starting valuation matters and what costs and countries change.

Funds that tidy up the shop window before year end and companies that beat estimates by a penny. What research says, the cases sanctioned by the SEC and what to look at.

Fake orders to move the price and stocks inflated with exaggerated news. The Sarao, Coscia and JPMorgan cases, the influencers charged in 2022 and how to spot the signs.

Commission-free apps are often paid by whoever executes your orders. The Robinhood case, what research says about the real cost of a «free» order and why it is banned in Europe.