Bucket shop refers to a particular type of fraudulent

Fraud

In criminal law, a fraud is an intentional deception made for personal gain or to damage another individual; the related adjective is fraudulent. The specific legal definition varies by legal jurisdiction. Fraud is a crime, and also a civil law violation...

 business

Business

A business is an organization engaged in the trade of goods, services, or both to consumers. Businesses are predominant in capitalist economies, where most of them are privately owned and administered to earn profit to increase the wealth of their owners. Businesses may also be not-for-profit...

:

• Bucket shop (heraldry)
  Bucket shop (heraldry)
  An heraldic bucket shop is a heraldry company that will "sell" a coat of arms associated with the customer's surname, regardless of whether the customer can actually claim a relation to the original armiger....
  
  
• Bucket shop (stock market)
  Bucket shop (stock market)
  As defined by the U.S. Supreme Court a Bucket shop is "[a]n establishment, nominally for the transaction of a stock exchange business, or business of similar character, but really for the registration of bets, or wagers, usually for small amounts, on the rise or fall of the prices of stocks, grain,...
  
  

The term is used as a pejorative colloquialism

Colloquialism

A colloquialism is a word or phrase that is common in everyday, unconstrained conversation rather than in formal speech, academic writing, or paralinguistics. Dictionaries often display colloquial words and phrases with the abbreviation colloq. as an identifier...

 to refer to different kinds of business

Business

A business is an organization engaged in the trade of goods, services, or both to consumers. Businesses are predominant in capitalist economies, where most of them are privately owned and administered to earn profit to increase the wealth of their owners. Businesses may also be not-for-profit...

es, indicating that the speaker believes it is a fraud or scam

Confidence trick

A confidence trick is an attempt to defraud a person or group by gaining their confidence. A confidence artist is an individual working alone or in concert with others who exploits characteristics of the human psyche such as dishonesty and honesty, vanity, compassion, credulity, irresponsibility,...

. In this sense it might be used as a name for stock market

Stock market

A stock market or equity market is a public entity for the trading of company stock and derivatives at an agreed price; these are securities listed on a stock exchange as well as those only traded privately.The size of the world stock market was estimated at about $36.6 trillion...

, unregulated credit default swaps, or for heraldry

Heraldry

Heraldry is the profession, study, or art of creating, granting, and blazoning arms and ruling on questions of rank or protocol, as exercised by an officer of arms. Heraldry comes from Anglo-Norman herald, from the Germanic compound harja-waldaz, "army commander"...

 scams.

The term is also used of airline ticket consolidators

Airline consolidators

An airline consolidator is a specific kind of airline ticket reseller. Consolidators work through contracts with major carriers to manage blocks of airline seat inventory at reduced prices which they then sell. The main benefit being that fares through consolidators will be lower than published...

, though in this case there is no implication of fraud.