I've just noticed one thing that many people still don't understand. When looking at a company's financial statements, they often only focus on the profit figures and think, "Oh, this company is making a lot of money." But the truth is much scarier than that.

There are quite a few companies that show beautiful profits, but in their pockets, there's not a single baht of cash. Why is that? Because accounting uses a method called "accrual basis," which records revenue when goods are shipped to customers, even if the cash hasn't been collected yet. That's where cash flow comes into play. It’s the number that truly shows how much cash is actually flowing in and out of the wallet.

If you think of a company as a human body, profit is like the food that makes you feel temporarily full, but cash is the blood and oxygen that sustain the body. If the blood stops flowing, even if the body looks healthy, it’s useless.

The cash flow statement is divided into three important parts. The first is operating activities, which is the most crucial. This figure shows how much money the company actually earns from its core business, not from selling assets or borrowing money. The second is investing activities, reflecting how management views the future—whether they are investing for growth or "selling assets" to survive. The third is financing activities, which tell about borrowing, dividend payments, and share buybacks.

When reading this statement, start from the bottom line and see whether cash has increased or decreased. But be cautious: an increase in cash doesn’t always mean good news. If it’s due to borrowing, but the business is losing money, that’s very dangerous.

Next, check the "quality of profit" by comparing cash flow from operating activities with net profit. If cash flow is higher than profit, it indicates the company is actually collecting money well. If it’s lower, be careful—this could be due to uncollected receivables or excessive inventory buildup.

Digging deeper, look at the "changes in working capital." If receivables increase faster than sales, the company might be extending credit recklessly. If inventory increases faster than cost of goods sold, it means unsold stock and trapped cash.

The most used figure by professional investors is Free Cash Flow (FCF), which is cash flow from operating activities minus capital expenditures. A company with positive and growing FCF is the strongest investment target because it can pay dividends or buy back shares without borrowing.

Take Apple and Tesla as examples; the difference is clear. Apple has huge positive cash flow from operations, invests little, and uses excess cash to buy back shares and pay dividends—that’s a mature company. Tesla, on the other hand, is still heavily investing in building factories and developing projects. Its FCF may be temporarily negative, but that’s "good negative"—an investment in the future.

The case of Tupperware filing for bankruptcy is a good lesson. Falling sales caused continuous negative cash flow from operations. The company had no money to pay debts and couldn’t borrow more, ultimately leading to bankruptcy. If investors had looked at the cash flow statement, they would have seen the "blood flow" warning signs long ago.

When choosing stocks in 2026, look for consistently positive cash flow from operating activities, ideally exceeding net profit. This is the critical point that separates good stocks from problematic ones.

For investing, use FCF Yield as a criterion—compare it to bond yields. If FCF Yield is higher, the stock is undervalued; if lower, it might be overpriced.

Another precise indicator is detecting "conflicts." If the stock price hits a new high but cash flow from operations declines, it’s a warning sign that the company might be "cooking the books" or its business quality is deteriorating. Sell immediately.

For growth stocks without profits yet, don’t focus on P/E ratios. Instead, look at their "runway"—how long their cash reserves will last. If it’s only six months, the risk is very high.

For dividend stocks, verify whether dividends are paid from actual FCF. If the FCF Payout Ratio exceeds 100%, it means the company is "borrowing to pay dividends." Long-term, dividends will definitely be cut.

Remember: "Profit is opinion, but cash is fact." Spending time analyzing cash flow carefully will turn you from a "market follower" into a "game controller" who can see opportunities and risks before anyone else.