Final answer:
Securities traded between investors after initial issuance take place in the secondary market, which is crucial for the liquidity of financial assets.
Step-by-step explanation:
When securities are sold by one investor and purchased by another investor, the transactions occur in the secondary market. The secondary market is crucial for the liquidity of financial assets, as it allows securities to be traded between parties other than the original issuer after they have been issued for the first time. In contrast, the primary market is where new securities are issued by the original issuer directly to investors. Examples of transactions that take place in the secondary market include the buying and selling of stocks, bonds, and other financial instruments that have been previously issued.