Next inflation print: above the previous month?
How it resolves
You win on Yes if the next annual inflation number is higher than last month’s, and on No if it’s the same or lower (a tie counts as No, which matters more often than you’d think when figures are rounded to one decimal place).
What we'd look at
Honestly, most of the edge here is in the base effect. If prices shot up a year ago, that drops out of this month's annual number, so it can come in lower even though things are still getting more expensive, and we'd look at energy and food before anything else. We'd also check what the forecasters expect, since a print that matches them rarely moves anything.
About practice markets
The price here is simulated, which means nobody's on the other side and nothing you do will move it. We built it that way on purpose, because the habit we want you to pick up is checking a price against your own number before you trade, and that's far easier to practise when a mistake costs you nothing. Try putting in a probability that's a few points away from the price and watch what happens to the expected value and the Kelly stake (that's the whole course in miniature).