De Fac­to Exclu­siv­i­ty refers to an exclu­sive sit­u­a­tion that exists in prac­tice, even though it may not be for­mal­ly or legal­ly rec­og­nized. It aris­es from cir­cum­stances or prac­ti­cal fac­tors rather than an offi­cial rule or law. De fac­to exclu­siv­i­ty can occur, for exam­ple, when a com­pa­ny dom­i­nates a mar­ket due to its over­whelm­ing mar­ket share, effec­tive­ly exclud­ing com­peti­tors even if there is no legal or con­trac­tu­al bar­ri­er to entry.