Selling at 20% Profit Is Why You Never Build Wealth: 3 Iron Rules of Compounding to Multiply Your Gains

A stock rises 20%, you press sell right away — and then what? Then you never build wealth. It’s not because you don’t work hard enough, and it’s not because you are unlucky. It’s because the act of selling at 20% profit itself keeps your wealth stuck in place.

Have you ever felt this? You watch a stock go up, your heart races, your hands itch, you are afraid it will pull back, and you quickly sell to lock in the gain. After selling, you feel relieved and think you are smart. A month later you look back and see that stock kept climbing 40%, 60%. You only took 20%, and you still paid tax and brokerage. After that you don’t know what else to buy, and the cash just sits in your account losing value.

Have you repeated this cycle for years?

This article is for financial education only and does not constitute any investment advice. Each person’s financial situation, risk tolerance, and investment experience is different, and what works for others may not work for you. Please evaluate every investment decision on your own and consult a Taiwan-licensed financial advisor and tax professional.

Iron Rule 1: Your Real Loss Is Cutting the Compounding Time Axis

What I’m about to share with you is not some magic stock-picking trick or a secret indicator — it is the three iron rules that Taiwan retail investors can actually use, survive with, and let their money truly work.

The timing of your sale is not about how much you made, it is about where your money can go next.

Why Is Selling at 20% Wrong?

Taiwan Stock Exchange historical data tells us that from 2003 to 2023, the Taiwan Weighted Index delivered roughly 8% to 10% annualized returns over those 20 years, including the global financial crisis, the European debt crisis, and COVID-19 — every one of those made people doubt life. But as long as you didn’t cut at the bottom, it always came back, and made new highs.

Do you know what retail investors’ average annualized return was over those 20 years? According to Taiwanese academic research, retail investors’ overall performance has long lagged the broad market, and many are even at negative returns. The reason is not bad stock picking — it is trading too often, selling at 20% profit, cutting losses at 10%, the brokerage and taxes constantly eating into your principal, and the fact that you personally cut the compounding time axis.

This is the first underlying rule you must understand: your real loss is not ‘the part you didn’t make’ — it is the act of personally cutting the compounding time axis.

The Taiwanese financial education textbook definition of compound interest is clear: it is interest on interest, the process in which your principal plus realized gains continue to generate returns. But this process has a prerequisite — your money has to stay in the market working. Every time you sell at 20%, you forcibly interrupt that rolling process. Each interruption costs you not only the part that kept rising after the sale, but the break in the entire subsequent compounding chain.

The compounding time axis diagram

A 10-Year Comparison of NT$300,000

Let’s run some real numbers. You have NT $300, 000, an d y o u se l l e v er y t im e a p os i t i o ni s u p 20$ 300,000 turning into NT $420, 000. * * B u t y o u p a y b r o k er a g eo n e v er y t r a d e . T ai w an s t oc k t r a d in g b r o k er a g e i sc a pp e d a t 1.425‰, c ha r g e d o nb o t hb u y an d se l l, pl u s t h esec u r i t i es t r an s a c t i o n t a x o f 3‰ o n se l l . T w or o u n d - t r i p scos t y o u a r o u n d N T$ 6,000 to NT$8,000 in costs alone.**

Then your NT$420,000 has to find a new position, and you have to wait for an entry point. During that idle window, your money is sitting still and not working for you.

Now flip it: the same NT $300, 000, b u y a T ai w anma r k e t - c a pE T F l ik e t h e 0050 or 00850 t ha tt r a c k s t h e T ai w anma r k e t, h o l df or 10 y e a r s, a ss u m e 8$ 300,000 ends up at about NT $640, 000 * *; a t 6$ 530,000. You do nothing — you just let compounding work for you.

This is not telling you to do nothing at all. It is telling you that the cost of constant trading-in and trading-out is far higher than you imagine.

Iron Rule 2: What You Think Is Profit-Taking Is Actually ‘I Don’t Know What to Do Next, So I Run’

Now we move to the second iron rule — this is the part most Taiwanese retail investors cannot see through.

You think you are profit-taking, but what you are actually doing is driving your money out of a high-quality asset and into a迷茫 state where it has nowhere to go.

The essence of profit-taking is: when your capital has a better place to go, or when the fundamentals of the asset you hold have changed, you realize the gains and move them to a more efficient place. Profit-taking is not a reflexive sell when you see a 20% gain — that is ‘I don’t know what to do next so I run first.’

These two things are very different. The problem for many Taiwanese retail investors is not poor stock-picking — it is not knowing where to put the money after selling. After selling, the cash sits in a savings account at 0.2% interest, unable to outrun inflation. Taiwan’s CPI spiked above 3% in 2022 and has averaged around 2% in recent years. Money sitting in savings is actually losing real purchasing power every year, not preserving it.

So the decision to sell cannot be made based on how much you made alone — it must be made on whether the money can go somewhere better than where it is now. If the answer is ‘I don’t know,’ then you should not sell.

Iron Rule 3: You Have One Bet, Not Asset Allocation

The third iron rule is the mistake Taiwanese retail investors are most likely to make in a bull market, and the root reason they get crushed in a bear market.

You haven’t built asset allocation — you only have one bet. Many Taiwanese investors’ portfolios are just a few stocks, or all-in on one sector — for example, all-in on semiconductors, all-in on tech. When the market is good, you feel invincible, but in 2022 the Taiwan Weighted Index fell from 18,619 to a low of 12,629, a drop of nearly 32%. If you were a retail investor all-in on TSMC or tech names, your paper losses could have been even deeper.

Many people couldn’t hold it through that year’s low, sold at the bottom, and when the market rebounded in 2023, they weren’t in it. This is not a luck problem — it is the inevitable cost of not having asset allocation.

The standard definition of asset allocation is spreading capital across asset classes with low correlation, with the goal of keeping the overall portfolio’s volatility within a range you can tolerate under different market environments. This is not buying a bunch of stocks for the sake of diversification — that is diversifying stock-specific risk, not asset allocation. Real allocation is managing the proportions between stocks, bonds, and cash or cash-equivalents.

A 4-Year Comparison of NT$500,000

Same NT$500,000, two people starting at the beginning of 2020:

The first goes all-in on Taiwan stocks. From 2020 to 2021 the market surges and the account nearly doubles, but in 2022 it drops 32%, and they can’t hold it and exit near the bottom, with only about NT$600,000 actually locked in.
The second person allocates 60% to a Taiwan market-cap ETF, 30% to bond funds, 10% cash. When the 2022 crash hits, their portfolio drawdown is contained at around 15% to 18%, and they don’t exit at the bottom. In 2023, when the market rebounds, they fully participate in the recovery. Over four years, annualized return is around 6% to 7%, NT $500, 000 b eco m esc l ose t o N T$ 650,000 — and during the process they didn’t lose sleep, and didn’t cut at the bottom.

Which outcome is better? Not the one with the highest return — the one you can actually see through to the end without exiting at the worst possible time.

Asset allocation vs all-in comparison

Many people in Taiwan use the age rule when doing asset allocation: 100 minus your age equals the percentage you should hold in stocks. The formula itself is fine, but in Taiwan’s environment there is a severely overlooked variable — your labor pension account.

Taiwan’s Labor Pension Act requires 6% of your monthly salary to be mandatorily contributed to your labor pension account. The money is managed by the government with a guaranteed minimum return, and it is effectively part of your overall asset allocation. But most people don’t include their labor pension balance when calculating their stock allocation ratio, so stocks are actually a higher share of your total assets than you think, because the labor pension portfolio also has equity exposure.

The correct approach is to add your labor pension balance to your self-directed stock holdings when calculating your overall asset allocation, and only then decide how your additional investment portfolio should be allocated. This is a detail that many investors with five years of experience have never done.

Taiwan’s stock dividends and cash dividends can be reported on individual income tax in two ways: combined taxation or separate taxation. The separate tax rate is 28%; combined taxation is based on your comprehensive income tax bracket.

Which one is more favorable for you depends on your comprehensive income bracket. Many people chase high dividend-yield stocks without ever calculating the actual after-tax return. The result is that the appeal of high yield is heavily eroded by tax.

It is recommended that before filing your taxes each year, you use the Ministry of Finance’s online calculator to run both filing methods, and picking the right one can legally save you anywhere from a few thousand to tens of thousands of NTD a year. This is not a gray area — it is a choice the law gives you, and not using it is just giving money away to the tax authority.

4 Operational Iron Rules

Iron Rule 1: The Money Will Not Be Needed Within 3 Years

You must first confirm the money will not be needed within 3 years. The longest stretch in Taiwan stock history from a high to recovering that high was the 2000 tech bubble, where the TAIEX fell from 10,256 to 3,411, taking nearly 13 years to recover its previous high.

If the market takes three years to recover, will your life fall apart because this money is locked up? If yes, this money should not be in the stock market.

Iron Rule 2: Monthly Investment Cannot Exceed 30% of Monthly Income

The amount you invest each month cannot exceed 30% of your after-tax monthly income, unless you already have a complete emergency fund and insurance coverage. For those starting a family, this ratio should be even more conservative.

Iron Rule 3: You Must Know What You Are Buying

If you buy a stock or an ETF and cannot articulate its basic logic, you should not buy it. You don’t need to become an analyst, but you should be able to explain in two sentences why this thing is worth holding.

Iron Rule 4: Decide the Sell Conditions Before You Buy

Whether it’s a stop-loss or profit-taking, you need clear, predefined conditions — not feelings. The stop-loss condition can be a fundamental change, or breaking below a level you can accept, but it cannot be a panic reaction to the number on the screen.

4 Action Steps to Implement

Step 1: Calculate Your Real Stock Allocation

Open your online banking or brokerage account, list all your current investment positions, add your labor pension balance, and figure out what your current total equity exposure is. Compare it with your age and risk tolerance to see if the ratio is reasonable. If you are 50 years old and stocks are above 70%, you need to seriously consider adjusting.

Step 2: Set Up Auto-Debit for DCA

Start with 10% of your after-tax monthly income — don’t overthink it, just get moving. Taiwan’s major brokerages, including Yuanta, Fubon, and Cathay, all offer DCA services for ETFs, with minimum thresholds ranging from a few hundred to NT$1,000. You can set this up today and let it run automatically.

Step 3: Check Your Labor Pension Account Once a Year

Check your labor pension balance at least once a year, and understand what your labor pension investment portfolio is. This number affects your overall asset allocation decision.

Step 4: Run a Dividend Tax Simulation Before Filing Each Year

Before filing taxes each year, use the Ministry of Finance calculator, run both ‘combined’ and ‘separate’ taxation, and choose the most favorable method for you. In a year, this can legally save you tens of thousands.

Conclusion: Leave the Time Axis for Your Money

The timing of your sale is not about how much you made — it is about where your money can go next. If you don’t have a better place, don’t sell. Leave the time axis for your money — it will do things for you that you cannot imagine.

Go back and review your past trade history. Look at what happened to those stocks you sold at 20%. Didn’t most of them keep going up? Didn’t you have nowhere to put the money after selling?

Next time you face a 20% gain, ask yourself two questions: Where will this money go after I sell? Is that place better than where it is now? If the answer is ‘I don’t know’ or ‘no,’ take your hand off the sell button.

Let your money stay in the market. Let compounding work for you for 10, 20, 30 years. That is the only path for Taiwanese retail investors to actually turn their lives around.

Disclaimer: All content in this article is for financial education only and does not constitute any investment advice. Each person’s financial situation, risk tolerance, and investment experience is different, and what works for others may not work for you. All investment decisions should be made based on your own financial situation and risk tolerance, and you should consult a Taiwan-licensed financial advisor and tax professional. All figures and estimates cited in this article are based on specific assumptions and do not represent a guarantee of actual investment results. Markets carry risk — please do your homework before investing.