Most bond market trading is done $$over the counter$$ where the trades are individually arranged by a broker who puts together the seller of the bond and the buyer of the bond. Why aren$$t more bonds traded in exchanges such as the New York Stock Exchange?

For most bonds, legal restrictions require that all investors be $$registered$$ investors to prevent ordinary people who aren't sophisticated investors from getting into bond investing.

For most bonds, the trading is said to be $$thin$,$ meaning that days could go by and there are NO trades for that bond.

For most stocks, the trading is said to be $$thin$,$ meaning that days could go by and there are NO trades for that stock.

For most stocks, legal restrictions require that all investors be $$registered$$ investors to prevent ordinary people who aren't sophisticated investors from getting into stock investing.