Partyhat

Partyhats, abbreviated phats, are obtained by opening Christmas nippols, dropped during the 2001 Christmas event. There are six different coloured partyhats, all with the same shape and size (red, yellow, green, blue, purple, and white). When worn by a player they resemble a crown. Because they are discontinued, they are very rare, much sought after and worth billions of coins, although they don't offer any stat bonuses. These are currently the most valuable objects in RuneScape. Partyhats are used to hold large sums of cash, because the gold coin limit is 2.147B and these hats are gaining wealth over time. Due to their nips, these items hold a much higher Street value than their value on the Grand Exchange. In Runescape Classic, the price of partyhats was drastically changed after players abused a glitch by creating many partyhats. (See Partyhat duplication glitch for more info.) Due to their high price, they have become recognised as a symbol of wealth in the game by players and non-player characters alike.

Over time, the volume of partyhats has been diminishing. The much smaller number of players when partyhats were released meant that not as many were acquired when available. Also, at the time of the release, partyhats were virtually worthless, meaning many players discarded them immediately. The majority of the few players who held onto them eventually quit RuneScape or were banned, leaving the number of active players with party hats at a very, very low number. The volume of partyhats diminished even further when players quit Runescape due to the EoC update and even alching the partyhat.

Surprisingly, partyhats do play a pivotal role in the RuneScape economy. Players will use these items as investments, cash placements, staked items, and collectables. They are used as cash holders for players because of the stability of the item. Majority of partyhats are traded in world 2 around the grand exchange, but collectibles players wishing to buy or sell a partyhat may either have to advertise on the RuneScape forums, leave it in the Grand Exchange, or trade at much lower/higher prices to accommodate the few players that are willing to trade party hats.

The Partyhats
There are six partyhat colours: white, blue, red, green, yellow, and purple. Each partyhat is worth a different price. Price value greatest to least of each colour is: blue, white, red, green, yellow and purple. This is by ranked by the street value they are traded for. In RuneScape Classic, all partyhats were simply named "partyhat" and were only distinguishable by the colour of the item. However, purple partyhats were coloured magenta in RuneScape Classic.

Please note that the price of a Blue or White Partyhat is not 2,147,483,647 GP,  but much higher, due to the GE not being able to support a larger number of coins (see Max cash).

Jagex's Stance on Partyhats
Jagex have stated that they do not wish to recreate the effect that partyhats have had on RuneScape's economy. This is the reason that tradeable holiday drops were replaced with events with non-tradeable rewards. After releasing the fish mask, Jagex changed its stance on tradeable discontinued items, with the mask being the first tradeable discontinued item released since the Santa Hat.

Mod Mark said that if a large number of discontinued rares fell victim to a botnuke, Jagex would look at ways to re-introduce them, probably via the Grand Exchange.

April Fool's Day 2012
As part of the April Fool's celebration in 2012, Jagex released an update claiming "Green p-hats ... are lying strewn throughout the streets of Lumbridge, Varrock and Falador." Rather than Green partyhats being dropped, peahats were dropped.

Trivia

 * When examined in Runescape Classic, partyhats say "Party!!!".
 * It is rumoured that it was no longer possible to High Level Alchemy or Low Level Alchemy a partyhat. This is not true, the partyhat will simply disappear. The player however, will be prompted with a confirmation message as for all items with a Grand Exchange value of 500,000 coins or higher.
 * Previously bald players with partyhats grew hair when wearing one. This has been fixed by Jagex.
 * A graphical glitch that came out few months back allowed hair to stick out of the partyhat. It also enables you to see your hairdo, when in fact most hairdos cannot be seen whist wearing a partyhat. Un-equipping & re-equipping the partyhat will cause the latter to happen. The glitch can be induced again by re-logging in to RuneScape.
 * Partyhats have become the most expensive wearable items that offer no bonuses.
 * The Wise Old Man has an updated version of a partyhat, which has not been updated for players. Jagex stated at the time of release of Love Story that players would not receive this update (the Wise Old Man was updated at the release of Love Story).
 * When pulling a Christmas cracker it says "Hey I got the cracker!" Although one receives a partyhat and the other a random item.
 * Uri from Treasure trails sometimes makes a reference to partyhats saying, "Once I was a poor man, but then I found a partyhat."
 * Mod Mark has stated that black party hats were planned to be released in-game but they were withheld because they were deemed "not festive enough".
 * A common misconception is that partyhats increased in price after the free trade update, even though they crashed. However, the Grand Exchange price only rose because the price cap was removed, allowing the price to be updated.
 * In the quest Love Story, it was possible to take an unwearable partyhat outside the cutscene.