A more thorough explanation:

Signature guarantee is a way to make sure that a signature is real and to protect against identity theft when transferring or selling property, such as stocks. This is done through a registered financial institution, which charges a small fee to provide the guarantee.

For example, let's say you want to sell some stocks that you own. The buyer wants to make sure that you are the real owner of the stocks and that no one else is pretending to be you. So, you go to your bank and ask for a signature guarantee. The bank checks your identification and verifies that you are the true owner of the stocks. They then provide a stamp or seal on the paperwork to show that they have guaranteed your signature.

If someone tries to forge your signature and steal your stocks, the financial institution that provided the signature guarantee will be responsible for any losses. This helps to protect both the buyer and the seller from fraud.

Signature guarantees are commonly used for transferring ownership of stocks or other assets that are in paper form. They provide a way to ensure that the transfer is legitimate and that everyone involved is protected.