Yes, and more often than most people expect. The honest answer is more specific than that, though: whether cruise prices go down after booking depends almost entirely on which line you booked.
CruiseSignal records the publicly listed fare for every cabin category, at every rate, on every sailing it tracks. That gives a direct answer rather than an estimate, and the full data is published with the current figures, rather than summarised here where they would go stale.
What the record shows
On most of the lines we track, more fares later fell than held. Carnival is the outlier: most Carnival fares stayed where they were, and the ones that fell moved by less.
The size of a drop follows the same split. On the active lines the median drop, among fares that fell, is several hundred dollars on a cabin for two, and one drop in ten runs well into four figures. On Carnival drops come less often, but the biggest still run to several hundred dollars a cabin. Long itineraries and suites produce the largest single falls everywhere.
Booking the same cabin on two different lines gives you very different odds that the price will move afterwards, and that is not something the lines advertise. The exact figures for each line, updated weekly, are on the price data page.
Why fares move at all
A cruise ship is a fixed number of cabins sailing on a fixed date. An empty cabin earns nothing, and it also spends nothing onboard, which is where a large share of the margin comes from. So the price is managed continuously against how full the sailing is.
That produces movement in both directions. Fares rise on sailings that are selling well and fall on ones that are not, and the same itinerary in two consecutive weeks can behave completely differently.
What it means for a booking you already hold
A fare that falls is only worth money if it falls while you can still claim it, which in practice means before your final payment date on most lines. That makes the useful question narrower than "do prices drop". It is "did the price of my exact ship, sail date and cabin category drop while my claim window was open", and the only way to answer it reliably is to check continuously.
Larger cabins move in larger absolute amounts. A suite that falls by the same percentage as an interior is a much bigger cheque, which is why the tables on our price pages break the numbers out by cabin class rather than averaging them together.
The part that catches people out
Prices going down is not the same as you being owed something. Every line excludes group rates, casino offers, travel agent fares and third-party sites, and most exclude a list of their own promotional fare codes. A lower number that falls into one of those buckets is real but not claimable.
That is worth knowing before you spend an afternoon on hold.
