Just-in-time inventory system is a management strategy where raw-material are ordered from suppliers directly according to production schedules.

Just in case is an inventory strategy where companies keep large inventories on hand to minimize the probability to be sold out of stock.

Junior security is a security that has lower priority claim than other securities with accordance to the income or net worth of its issuer. 

Junk bonds are the type of bonds that carry a higher risk of default than most of the bonds issued by corporations and governments. 

Jitney is a broker who has access to stock exchange and performs trades for those who do not have the access.

A J-curve is a trading pattern that shows a big loss followed by a very steep gain. In a chart this would look like "J".

Jobber is the slang name given to the market maker on London Stock Exchange. The term also describes a small-scale wholesaler or middleman in the retail goods trade.

Justified wage is a fair income which is determined by the market dynamic, work experience, skills and education level. It is a perfectly balanced level of high wage that will attract new workers and of low-enough level that will enable the employer to offer it.

Job lot is a futures contact with volume smaller than the level needed for regular contract. They exist in order to add to the liquidity of the futures by letting smaller participants to enter the market.

Joint is a transaction agreement procession situation when all of the included parties are acting in unison.