Turnips function as in-game stocks, known as the Stalk Market in-game.
To buy turnips, you must find Joan, the turnip selling boar, on your island. Joan can be found walking in your town from 6 AM to Noon every Sunday. She will sell you turnips in batches of 10 of a price between 90 and 110 bells per turnip.
Turnip Storing and Rotting
Turnips will rot at 6 AM on the following Sunday. If they rot, you will be unable to sell them to Re-Tail, and instead Reese will charge you to dispose of turnips. It's in your best interest to have a garbage can ready in your town as a public works project or one in your home as furniture before diving into the stalk market.
You can time travel FORWARD in time up to a week before your turnips rot. However, any instance of BACKWARDS time travel will instantly rot them. If you have turnips stored, It's best not change the in-game time at all.
You can check the selling price of turnips by speaking to Reese at Re-Tail and ask about "Turnip prices". The price changes twice a day, one in the morning when Re-Tail opens and again at Noon.
Reese will not purchase your turnips on Sunday, as that is the day you buy turnips.
Throughout the week, the price of turnips will change. It will follow one of four patterns (helpful to learn them before buying turnips). (Remember, turnip prices will change twice in a day, in the morning and noon, so check for these patterns twice!)
This pattern is unpredictable and thus there is no way to understand when to sell entirely. With this pattern, the price will rise and fall at random to a price up 200 bells per turnip max.
The price per turnip will be under 100 bells at the start of the week. It will constantly decrease throughout the week, with no increase of price.
This pattern begins with declining prices, followed by 4 increasing prices. The maximum price being between 180 and 250 bells per turnip on the 4th increase. After the 4th increase, price will decline for the remainder of the week.
Similar to the Small Spike this one starts with decreasing prices, followed by 3 increasing prices. The maximum price will happen on the 3rd increase with a maximum of 400 and 600 bells per turnip, then decreasing afterwards.
Predicting Your Pattern
Predicting the pattern you have been given for the week is simple and straight forward if you follow these steps, to eliminate patterns.
Look for an increase in price. If you have an increase you can rule out the Decreasing Pattern. If you do find an increase, move onto step 2.
After your first increase, check for the price after your first increase. If the price immediately decreases, you have the Random Pattern. However, if you get another increase after the first one, you can safely assume you have one of the Spike Patterns, if this is the case move onto step 3.
Check for the price after your second increase. If you have 2 increases of price in a row, the 3rd increase will tell you which pattern you have. If your price is above 300 bells, you have the Large Spike Pattern. However, if your 3rd increase is not too high, you most likely have the Small Spike Pattern.
Here are a few tips to help you on your way with the stock market!
- If you find yourself with the Random Pattern there will unfortunately no way to predict the next price, so constantly check. Usually, there are 2 prices above 100 bells per turnip, so you should sell on your second random increase.
- If your price does not increase by Thursday Afternoon (second price change for Thursday) you have the Decreasing Pattern, if you do, sell your turnips immediately to avoid further losses.
- If you find yourself with a Spike Pattern after step 2, you can easily figure out which one you have with your 3rd increase. With a Large Spike Pattern, sell immediately after your 3rd increase.
- With a Small Spike Pattern, you should wait for the 4th increase in a row before selling, as that will be your highest price. However, if you do not wish to risk it you can sell on your 3rd increase.