A holding's detail plots its dividend history: the dividend per share for up to its last 30 payments. That's about seven and a half years for a company that pays quarterly and fifteen for one that pays twice a year, so check the dates along the bottom rather than assuming a span. Amounts are per share, so your own buying and selling doesn't move the line. The newest point can be an estimate of the next payment, worked out from the company's current annual rate, rather than a declared amount.
Three shapes are worth recognising. A staircase, each year a step above the last, is a steady dividend growth rate. A cliff, where payments drop and then carry on from the lower level, is a cut followed by rebasing. And a zigzag — a smaller payment, then a larger one, every year — is usually nothing at all: many UK companies pay a smaller interim dividend and a larger final. Compare each payment with the same one a year earlier before reading a drop as a cut. A single spike is usually a special dividend, which the chart doesn't mark.
Compare like with like: this year's interim against last year's, this year's final against last year's.
Educational content only. It is not personal financial advice.