A Decade in the Markets: My Trading Journey from Seoul to Ingolstadt
"Ten years is not a career, it is not a hobby, and it is not a story with a clean ending. It is just a long enough sample size to have some idea which of your mistakes are structural and which were bad luck."
Every trading blog eventually gets around to writing the "here is my journey" post. I have been putting mine off for years, mostly because I did not want to write the version that lies. The clean arc where the naive twenty-something makes bad trades, discovers a framework, becomes profitable, and rides off into the sunset. That version reads well. It just is not what happens to most people, and it is not what happened to me.
What follows is closer to the truth. Ten years, three market categories (Korean equities, US options and futures, crypto), one blown account, one country change, one currently-paused live-trading practice, and one blog you are reading right now. If you are somewhere in the middle of your own journey, some of this may be useful. If nothing else, it is one data point on how one specific engineer-turned-trader spent a decade in the markets and what he took away from it.
🔼 The archive that made a decade legible. Folders by year and by theme — not a strategy on its own, but the stubborn habit of writing things down before clicking anything.
📋 The chapters
- 2016 — Seoul, Kiwoom, and the first account I opened for the wrong reasons
- 2017-2018 — Chasing the winning streak that never quite existed
- 2019 — The options blowup nobody warned me about
- 2020-2021 — Crypto on Upbit, and the illusion of being a genius
- 2022 — Moving countries, changing brokers, losing my grip
- 2023-2024 — Trying to trade around a demanding day job
- 2025 — The audit that changed everything
- 2026 — Paused, writing, waiting for the framework to prove itself
- What I would tell 2016 me
1. 2016 — Seoul, Kiwoom, and the First Account I Opened for the Wrong Reasons
I opened my Kiwoom Securities account in the spring of 2016. I was in my early thirties, living in Seoul, working as an embedded software engineer, and — this is the part I usually skip — I opened the account because a colleague at work was making noticeably more money than me and told me the difference was a KOSDAQ small-cap he had bought a month earlier.
That is not a strategy. That is peer pressure with a login screen. But it is why I opened the account, and pretending otherwise would be dishonest.
The first six months were a blur of KOSDAQ names I could not identify today. I read a couple of Korean-language trading books, watched a lot of YouTube, and confused activity with progress. I made money on my first three trades, all by accident, and lost it back over the next fifteen, which is a very standard opening chapter and one I now recognize as the market's way of collecting a tuition fee.
By the end of 2016 my account was roughly break-even after fees, which felt like a disaster at the time and looks, in retrospect, like a rare piece of luck. Most people who open accounts the way I did lose meaningfully more in year one.
2. 2017-2018 — Chasing the Winning Streak That Never Quite Existed
Years two and three are the ones I remember with the least fondness. I had absorbed enough terminology to sound competent — moving averages, RSI, MACD, Fibonacci retracements — and I built spreadsheets that made me feel like I had a system when I really had a habit.
🔼 One turnaround workbook out of many. L&F in late 2019, quarterly EPS collapsing across the board — worst quarter down 288% year-over-year — and I still had a target price of 55,000 KRW pencilled at the top. Every ticker got a workbook before it ever got a position. I mistook the habit for a system for a long time.
The pattern was recognizable and it is worth naming clearly. I would win a few trades, get bold, size up, take a loss that erased the winning trades and then some, size back down defensively, win a few more, and repeat. The account did not grow. It oscillated. If you had looked at just the win rate you might have thought I was a mediocre-but-functional discretionary trader. If you had looked at the equity curve, you would have seen a slightly downward-sloping sawtooth.
The two things I know now that I did not know then:
- Position sizing was doing far more damage than my setup selection. I was picking trades that were roughly 50/50 and turning them into a losing system by risking three times as much on the trades I was excited about.
- I was not logging trades in a way that would ever teach me anything. My "log" was a spreadsheet with entry price and exit price. That is not a log, that is a receipt.
3. 2019 — The Options Blowup Nobody Warned Me About
In 2019 I discovered US options and, more specifically, I discovered that a small account could theoretically grow into a large account very quickly if the underlying moved in the right direction the right amount within the right time window. I read a couple of books, watched a lot more YouTube, and concluded — incorrectly — that I understood the greeks.
The trade that broke that misunderstanding was a directional call spread on a tech name whose earnings I had strong opinions about, most of which turned out to be wrong. The position was too large relative to the account. The IV crush on the wrong side of the move was worse than the price move itself. Within two days I had lost about two-thirds of that specific sub-account. I closed the remaining position, paid the assignment fees, and stared at my laptop for a while.
The lesson from that trade was not "options are bad." Options are a tool, and plenty of thoughtful traders use them well. The lesson was that the leverage in an instrument you do not deeply understand will find you before your understanding catches up. If I had risked the same conviction on the underlying stock, the loss would have been recoverable in weeks. The options structure turned a wrong opinion into a compressed lesson I paid for in cash.
I stopped trading options after that. I have not been back. That may have been an overreaction, but ten years in, I still think it was the right call for my temperament.
4. 2020-2021 — Crypto on Upbit, and the Illusion of Being a Genius
I opened my Upbit account in early 2020. Everyone in Seoul opened crypto accounts in 2020. The moves were dramatic, the community was loud, and the illusion of expertise was very easy to sustain when everything was going up.
I did well in 2020 and the first half of 2021. Well enough that I briefly considered telling people I was "in crypto full-time," which is the kind of sentence you should be immediately suspicious of when it forms in your own head. I was not a full-time trader. I was a software engineer with a good year in an obvious bull market. Those are different things.
The second half of 2021 through 2022 quietly took most of it back. Not in one dramatic drawdown — that would have been more instructive. It bled out in small chunks across altcoin positions I could not bring myself to cut. Loss aversion in crypto is a particularly nasty version of the general disease, because the volatility makes every stop-out feel like it will reverse the next day, and sometimes it does, which trains you to hold the ones that do not.
The takeaway I have carried forward: a good year in an obvious environment tells you almost nothing about your skill. It tells you about the environment. The signal about your skill comes from the neutral or hostile years, when the environment stops covering for your worst habits.
5. 2022 — Moving Countries, Changing Brokers, Losing My Grip
I moved from Seoul to Ingolstadt in 2022. There is a whole set of reasons — a good job offer, a life stage that could support the change, the mundane accumulation of factors that most cross-country moves come down to — and they are not the subject of this post. What matters here is what the move did to my trading.
Practical things I underestimated:
- My Korean brokers did not translate cleanly to German residency. I ended up moving pieces of my portfolio across accounts and jurisdictions in a way that fragmented my attention.
- The time zone shift meant the US market opened at 3:30 PM Ingolstadt time — right in the middle of my work day, not the middle of my evening the way it had been from Seoul.
- The learning curve of a new country (language, taxes, health system, social life) burned a lot of the cognitive budget I had previously spent on markets.
The result was a strange half-trading year where I still had positions on, still checked charts, but was making decisions with maybe 30% of the focus I had brought to the same instruments a year earlier. Unsurprisingly, the P&L reflected that. I did not blow up. I just quietly gave back the pandemic-era gains and told myself I was "adjusting."
6. 2023-2024 — Trying to Trade Around a Demanding Day Job
By 2023 the move had settled and the new job had become considerably more demanding than the job I had left. I have written about this in more detail in the Why I Paused Live Trading post. The short version: embedded systems work in automotive and defense is not the kind of work that leaves you with mental cycles to spare at 8 PM. It carries context in your head. You debug something at your desk, and then you keep debugging it in the shower, on the walk home, and in bed.
I tried to trade around that anyway for about eighteen months. The results were exactly what you would predict if you had never met me: not disasters, not glory, just a slow drift toward break-even after commissions. The account was doing something that looked profitable if I zoomed in on the good weeks and something that looked mediocre if I zoomed out to the year.
I started building frameworks in this period, mostly as a way to convince myself I was making progress even when the P&L would not confirm it. Some of those frameworks — the 5-Layer Framework, the Volume Checklist — are the ones I still use as reference points today. Others turned out to be elaborate rationalizations for trades I wanted to take anyway. Sorting one from the other took the audit that came next.
7. 2025 — The Audit That Changed Everything
Somewhere around mid-2025 I sat down with two years of trade logs and did something I had been avoiding for the entire decade. I actually classified each trade by which layers of my framework it satisfied at the moment of entry.
The numbers were uncomfortable. Trades that satisfied all five layers were materially better than trades that satisfied four or fewer, both in win rate and in expectancy. That would have been a fine result — except that the full-layer trades represented only about a third of my total volume. Two-thirds of what I had done in 2023 and 2024, by my own newly-tightened standards, was trades I would not have taken if I had actually been enforcing the framework I claimed to be using.
You can respond to that audit two ways. You can decide to be more disciplined next time — which every trader who has ever run this audit tells themselves, and which about ten percent of them actually manage. Or you can pause, get the framework written down cleanly, and refuse to click again until you have proven, out of sample, that you can filter this way.
I went with the second one. That is the pause that turned into the current writing phase.
8. 2026 — Paused, Writing, Waiting for the Framework to Prove Itself
🔼 Current desk, current watchlist, no positions. Ten years compressed into a documentation phase.
Which brings us to right now, July 2026. I am not taking live trades. I am reviewing old trades in batches. I am writing this blog. I am building small Pine Script utilities on GitHub. I am observing markets without acting on them, which is a strange kind of discipline that I underestimated before I tried it.
If the pause was going to be indefinite, this would be a retirement post. It is not. The plan is to return when the framework has held up for six months of forward observation on paper, when I can articulate why each specific trade meets each of the five layers in one sentence, and when my day job leaves me enough cognitive room to give each trade the focus it deserves. Those are conditions, not a timeline. I have stopped setting timelines because setting timelines was part of what got me here.
9. What I Would Tell 2016 Me
The temptation with these posts is to end with a list of principles that sound profound. I have avoided that in the body of this piece deliberately, but at the end I will allow myself a short version, with the caveat that these are my lessons from my sample of one, not universal truths.
Log everything from day one, including your reasons. The receipt-style log I kept for years taught me nothing. The reason-based log I keep now would have saved me years if I had started in 2016.
Position sizing is the trade. Setup selection is the marketing. If you fix the sizing, the setup selection matters much less than you think. If you get the sizing wrong, no setup can save you.
Leverage before understanding is a very expensive form of learning. The 2019 options blowup taught me the same lesson I could have learned from a much smaller equity trade if I had been patient.
Good years lie to you. The 2020 crypto year told me I was a genius. The 2022 crypto year corrected the record. Both years mattered less than the boring 2023-2024 period, because that is where the actual signal about my skill lived.
Life stages are part of the trade. The version of me that could trade evenings from a small Seoul apartment in 2018 is not the same person as the version living in Ingolstadt in 2024 with a heavier job and less empty time. Pretending they are the same trader — and expecting the same process to work — was my most consistent mistake of the last four years.
Writing beats thinking. The frameworks I have written down for this blog are stricter and clearer than any framework I ever "had in my head." The exercise of writing forces exceptions into daylight, and most of them do not survive the daylight.
A pause is a legitimate move. Nobody in the trading corner of the internet talks about it, because you cannot monetize "I stopped for a while and thought about it." But it is a real thing that real people do, and sometimes it is the most productive thing you can do.
That is ten years. The next ten will look different. I hope some of them will look less like corrections of the previous ones and more like actual compounding. But I have been in the markets long enough to know that hope is not a plan, and this post is the closest I know how to get to writing down the plan honestly.
Thanks for reading, and see you at the next chart.
📚 Related Reading on This Blog
If this piece resonated, these companion posts continue the same threads:
⚠️ Educational Disclaimer
This post is a personal reflection for educational and informational purposes only. It is not investment advice, financial advice, trading advice, or a recommendation to start, continue, or pause any specific trading activity.
Trading involves substantial risk of loss and is not suitable for every investor. My personal journey is specific to my own situation, and nothing described here should be read as a general recommendation to follow the same path.
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About the Author
Dongmin Park is a software engineer with over 15 years in embedded systems (automotive and defense industries) and 10+ years of active trading across Korean equities, US options, MNQ futures, and crypto. He started trading on a Kiwoom Securities account in Seoul in 2016 and now lives in Ingolstadt, Germany, after relocating in 2022.
Coder Trader is an ongoing project to document where systematic engineering discipline meets discretionary trading. Say hi on X, look at the code on GitHub, or email hello@codertrader.com.
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