Bulljang rules and tips

Bulljang is a virtual market game that opens one board a day. The six stocks on screen are Riverside Electronics, Fireball Bio, Moonland Mining, Cloudnine Soft, Big Dumpling Foods and Bolt Delivery, and every one of the names is made up. They are not listed companies, and the prices are not taken from any real exchange.

You compete on one number: your return after ten days. Everyone who plays on the same day meets the same prices and the same rumors, so putting your scores side by side is a fair comparison. The board is built in your browser and every trade happens there too, so you need no account and what you bought never goes to a server.

The game imitates a trading screen, but its subject is rumors, not stocks. The fun is in reading the stories around a market: a stock with a rumor, a stock whose volume suddenly jumps, a day when a crisis is in the air. The prices are little more than a container for those stories.

Size of a game

You start with 1,000,000 won and a game lasts ten days. Buy and sell as much as you like in a day, and when you press the next-day button, the day passes and all six prices change at once. After the tenth day the market closes and your return is set by the total assets you have left.

How to buy and sell

The Buy button on a stock's row buys half of the most you can afford with your cash right now. Because it buys by halves, you can press it several times on the same stock to build up little by little. Selling has one button, Sell all, and one press clears that whole stock. Cash does not rise or fall in value.

Fees and the close

A 0.5% fee applies only when you sell, and buying is free. The game ends after ten days, and it also ends on the spot if your total assets drop below 300,000 won, which is 30% of your starting cash. The closing screen shows your return with a ten-day up-and-down row that you can copy and compare with friends.

From here on, this is what the app actually does. All of it is carried over exactly as written in the code.

How the prices are set

To answer the question we get most often: the prices in this game have nothing to do with real market prices. The game takes the day's date as a string, turns it into a single number with a hash, and a random number generator seeded with that number calculates all ten days of prices in advance. This app contains no code that fetches prices from outside. The stock names are made up so that they do not overlap with real companies, for the same reason.

On an ordinary day the move is roughly between minus 8% and plus 9%, tilted very slightly toward rising. Events scheduled for that day are added on top. A price never falls below 100 won. The same date always gives the same result, so if you open the game on another device that day, the prices are identical.

Rumor cards

One rumor appears each day, and the rumored stock moves sharply the next day, between 18% and 40%. Up is a little more common at 55%, but down is just as large. The direction is not shown on screen. The rumors and the prices are calculated together in advance, so a warning and its result never disagree. No rumor appears on the last day, because there is no next day.

The big players' pump and the volume flag

In every game one stock is the target of a pump. It rises quietly by 5% to 9% a day for two days, then jumps by 20% to 35% a day for two more, and on the last day it drops by 35% to 50%. That stock gets a volume spike flag from the day the buying starts. The important part is that the flag stays on until the last day, when the price drops. If you treat the flag turning off as your signal to leave, you are already late. Rumors avoid the pump stock, so the two events never land on the same stock.

The day a crisis rumor spreads

Some games have a financial crisis news item and some have none at all. When there is one, it appears somewhere from day 3 to day 5, and the day after the news, all six stocks fall together by about 15% to 25%. On the day a crisis is set, the crisis news takes the rumor's slot, so no rumor appears.

The fight with the short sellers

On day 6, short sellers move into one stock and push its price down for three days, by 8% to 14% a day. During this window you can post to the forum once a day, and if you collect three posts, a short squeeze goes off on the spot and that stock jumps 60% to 100%. If you fail to collect them, it falls another 10% to 20% at the end. The days when you can post run four days from the day they move in, so you have to start by the third day at the latest to fill all three. The drop while you post is the same in both branches, and only the final day of the showdown differs.

One more note: in real markets, organizing public opinion or running a pump to move prices is illegal under Korea's Capital Markets Act. The big players and the rally in this game are a device that makes fun of that world, nothing more.

Three retail investor perks

On the morning of day 3 and day 7, you pick one of three. The tip sheet tells you on the spot which stock is the pump, the stop-loss order sells a stock you hold automatically that day if it falls more than 15% in a day, and the lifetime membership removes the sell fee for the rest of the game. You cannot pick the same one twice, so your second choice is one of the remaining two.

Saving and sharing

Your progress is saved in this browser along with today's date. If you close the window or reload by mistake, you pick up where you left off. When the date changes, yesterday's save is discarded and a new game opens, and you can't resume yesterday's unfinished run, but games from the last 14 days can be played fresh from the Past games section on the home page. The score you copy after the close holds only the date, the ten-day up-and-down row, your return, and a badge such as Retail wins or Wiped out. Which stocks you bought and how much is not included.

What follows comes straight out of the rules above. It works because this app's code is built that way, and it does not carry over to anywhere else.

Cash is also a choice

Cash does not move, so if you buy nothing, your return is exactly 0%. Zero is not always a bad score. In a game with a crisis rumor, the player who stood aside in cash that day sometimes comes out ahead. On your first game, it is fine to spend a day or two just watching the prices to learn the flow.

Do not put everything into one stock

For a rumored stock, only the size of the move is certain and the direction is unknown. If you put all your money into one stock and it goes the wrong way, you can hit the 30% line in one move and the game ends right there. The Buy button buys only half of what you can afford for the same reason: it is meant to be built up little by little.

Sell less often

The fee applies only when you sell. If you rush and keep buying and selling, you get shaved down a little each time. The structure rewards you just for cutting trades you are not sure about, so it can help to start with a plan to move only once or twice a day.

After a few games, you get a feel for when events arrive. Put that feel into rules and it looks like this.

Count the big up days

The pump stock's surge lasts two days and the day after is the crash. The volume flag stays on through the crash day, so watching the flag alone will not tell you when to get out. What you can do is count the big up days by hand. If two big rises follow two quiet rises, the rules already say what kind of day comes next.

A crisis rumor is a one-day warning

The crisis news appears the day before the drop, not on the day of it. If you clear out on the day you see the news, you avoid the fall, and if you wait to react the next morning, it is already priced in. All six stocks fall together, so moving to a different stock does not help.

Decide whether to join the fight

Joining the short seller fight is a choice. If you buy the pushed-down price early and the rally succeeds, the stock jumps on the last day, but if you cannot fill all three posts, it heads for the floor. You have to start posting by the third day to fill three, so if you plan to join, it is safer to start posting from day one. A game where you leave it alone and watch the other stocks works just as well.

How to pick a perk

The tip sheet is worth the most when you pick it on day 3. If you learn the pump stock early, you get to use the whole rest of the run. The stop-loss order cuts a crash day off at the 15% line, so it keeps a game alive longer, and the lifetime membership favors people who sell often. The day 7 pick is one of the remaining two, so it helps to think on day 3 about which one you are leaving for later.

When a game ends in a few days

If your total assets fall below 300,000 won, the game closes before ten days are up. In most cases it is someone who put everything into one stock and then met a crash or a crisis. Just keeping half of your money in cash makes it very rare for one drop to end the game.

When you followed a rumor and it went the other way

A rumor tells you the size and not the direction. Up is only a little more common, so games where you followed it and got the opposite keep coming. If a rumor lands on a stock you already hold, cutting the position to half is a sensible way to narrow the swing inside this game.

When Buy only buys a little

Buy takes half of the most you can afford each time. Press it several times if you want more. Selling has no partial sale, so one press clears the whole position, and if you only want to trim a little, your only way is to sell everything and buy again. Keep in mind that the fee applies to what you sold.

When you want to go back to yesterday's game

The game is tied to the date, so once the day changes, yesterday's prices do not open again. Today's game is saved, though, so you can close it midway and it carries on as before. If you got a game you regret, wait for tomorrow morning. On a new date, the rumors and the pump are laid out from scratch.

Taking this game's rules outside

One last time, in writing: everything above applies only to the values this app makes up. A two-day surge or a crisis warned one day early is what this game's code decides, and it is not a property of any market. A good score here also means nothing outside. Enjoy it for fun, and when the game is over, walk away with just the score.