There are two different ways a category gets more expensive, and they call for different responses. One is a spike — a single month well above your average. The other is a trend — three or four months each higher than the one before. The first might be noise; the second almost never is.
Spike: one loud month
Your taxi spend is usually around ₴1,500, and this month it is ₴3,000. That is a spike. Often there is a plain reason: you were carless for two weeks, or it rained all month. A spike is worth noticing but rarely worth changing anything — check that you recognise it, then let it go. If next month is back to normal, it was just a bump.
Trend: the quiet climb
Now imagine delivery went ₴2,000, then ₴2,600, then ₴3,300 over three months. No single month looks alarming, but the direction is unmistakable. This is the one that actually costs you, precisely because it never feels like a decision. A trend is the signal to act: set a budget on the category, or look at what changed and decide whether the new level is one you are happy with.
How to tell them apart
- One month up, then back down → spike. Note it, move on.
- Each month higher than the last → trend. Decide deliberately.
- When unsure → wait one more month. A trend keeps climbing; a spike does not.
How Purple Wallet helps
The app compares each category against your own recent baseline, so both a one-month jump and a steady multi-month climb surface on their own. Finn distinguishes the two — a sudden spike versus a sustained upward trend — and may point out a category that is genuinely trending up, so you catch the quiet climb while it is still small enough to redirect.