What to check before buying a stock
Summary
A checklist is useful because it is boring: it forces the same questions on a company you like as on one you do not. The order matters more than the list. Understand the business before the numbers, and the numbers before the price.
If you prefer one clear verdict instead of scattered data, see the product overview.
1. What does it actually sell?
If you cannot explain how the company makes money in two sentences, stop. Everything below assumes you understand what you are valuing, and no amount of ratio work substitutes for that. Company profile and segment breakdown are on every stock page here.
2. Does it earn money doing it?
Revenue direction over several years, and whether profit exists at the bottom. A company growing revenue while losing more each year is a different proposition from one growing slowly and profitably — both can be good buys, but not for the same reason or the same holder.
3. Could it survive a bad year?
Debt against cash, and whether operating cash flow agrees with reported profit. Companies rarely fail because growth slowed; they fail because an obligation came due at the wrong moment. This is the question that separates a disappointing holding from a permanent loss.
4. What does the price already assume?
A good company at a price that already assumes everything goes right is not a good investment. Compare the valuation against rivals and against the company's own history — the method is set out in full on how to tell if a stock is overvalued.
5. Who else is buying?
Insider transactions are worth a glance, with the caveat that selling has many innocent explanations and buying has roughly one. Treat it as context, never as the reason.
6. What could plausibly go wrong?
Name three specific risks — customer concentration, a patent expiring, a regulator, a single supplier. "The market could fall" is not one of them, because it applies to everything and therefore distinguishes nothing.
7. Why do you want it, and what would change your mind?
Write both down before you buy. The second one is the step people skip, and skipping it is what turns bad news into something to argue with rather than something to weigh. You will never again be as objective about this company as you are right now, before you own it.
Where a tool helps, and where it does not
Gathering the evidence for steps one to five is what a research tool is for. Every US-listed common stock and ADR covered here has a free page, no account needed, showing whichever of those pieces exist for that company — coverage is thinner on smaller and less-reported names, and a section is left out rather than filled in when the data is not there. Steps six and seven are yours: no tool knows what you would accept as being wrong. None of this is investment advice.
Frequently Asked Questions
What should I look at before buying a stock?
Seven things, in order: what the company actually sells, whether it makes money doing it, whether it could survive a bad year, what the current price already assumes, whether insiders are buying or selling, what could plausibly go wrong, and why you want to own it. The order is the useful part — understanding the business before the numbers stops you from valuing something you cannot explain.
How long should this take?
A first pass is ten to fifteen minutes per company once the numbers are in front of you. That is enough to reject most of them, which is the checklist's real job. The ones that survive deserve hours, not minutes.
Do I need to read the financial statements myself?
Eventually, for a position you intend to hold. For a first pass the summary figures are enough: revenue direction, whether profit exists, debt against cash, and whether the cash flow agrees with the reported profit. If those four look wrong, the statements will not rescue it.
What is the most common mistake?
Skipping the last step. Deciding what would prove you wrong is uncomfortable, so people skip it, and then any bad news arrives as a surprise to be argued with rather than a signal to be weighed. Write it down before you buy, while you still have no position to defend.
Can a tool do the checking for me?
It can put the evidence in one place, which is most of the work. What it cannot do is decide whether the business makes sense to you or what you would accept as being wrong. Any tool that presents a single number as the answer to all seven questions is compressing away the part you actually needed.
Evidence & Sources
- Data sources used on Stock Expert AI include FMP (Financial Modeling Prep), Alpaca, Finnhub, Alpha Vantage, and SEC filings where available.
- Definitions follow standard investing terminology, with key terms explained inline in plain language where useful.
- Prices refresh when a page is viewed during US market hours and are not a real-time exchange feed; outside those hours they are the last close.
- This page is educational and does not constitute investment advice.
- All analysis is generated by AI models and should be verified with independent research.