Graceful Exit BOND market
Under DGF, primary DAOs are encouraged to be maximally open. This means anyone willing to follow a DAO's protocols may join or leave at will. In order to facilitate the ability to leave a DAO, the value of any member's contributions should be fairly compensated at any point when the member chooses to leave. A Graceful Exit BOND market allows a member to cash out, by converting their REP tokens to BONDs and sell the BONDs at market.
Overview
In most cases, when someone wishes to retire from a DAO, they would presumably stop participating and earning REP tokens, but continue enjoying the REP salary for the tenure of their remaining REP tokens.
However, any DAO has the option to give their members another option of a graceful exit through the BOND market. When someone wishes to exit a DAO and immediately cash out, instead of using the annuity function of the REP salary, they can convert their REP into a BOND with the same claim on the REP salary, but none of the powers of voting, or availability signalling. Then they can sell those BONDs on the BOND market. This allows them to achieve an immediate gain of cash if desired.
Security
This mechanism inhibits the natural market for REP tokens, since its existence ethically justifies the slashing of any REP tokens that can be proven to have been sold. Therefore the BOND market should, under most circumstances, prevent the existence of any REP market, which therefore inhibits 51% attacks.