The sparkline next to every price, explained
Next to most prices on the board, you'll see a small line chart — a sparkline. It's easy to skim past, but it's drawn directly from the same real data behind the "X% below 30-day median" badge, not a decorative flourish.
What it actually plots
The line is the route's trailing price history exactly as it stood before today, with today's actual price appended at the end and marked with a gold dot. That ordering matters: the median a deal gets judged against is calculated before today's price is added to the history (see how we rank deals for why), so the sparkline and the badge next to it are always describing the same underlying math, just in two different forms — one a number, one a shape.
No chart library, on purpose
The sparkline is a small inline SVG generated directly from the price data, not a JavaScript charting library. Sparkfare's frontend is deliberately framework-free — one more dependency for one small chart wasn't worth it.
Why some cards don't have one
A route with fewer than 2 combined data points simply has nothing to draw a line through — those cards show the price alone, no chart underneath. That's the same "Building history" honesty rule showing up in a different form: if there isn't real data yet, we don't fake a shape to fill the space.