In 4 weeks there is a planned protocol upgrade for Bitcoin Cash. This means that you need to run a newer software stack to continue participating in Bitcoin Cash after that day. It helps to upgrade early and avoid last minute surprises. In case you are running the ABC client, you need to switch to a different client as they choose to no longer be part of Bitcoin Cash after the 15th of November.
The upgrade fixes a problem with regards to block-times where today we sometimes get 15 block per hour, and sometimes it takes ages for a single block. This is a problem for services that want to get a number of confirmations. After the upgrade we should get much closer to the average of 10 minutes per block which makes things more predictable again.
More: The story of how BCHs 2020 DAA came to be.
Most people that participate in BCH in some way need to upgrade their full node or wallet. So the answer most likely is: yes.
If you just use a wallet on your desktop or phone, you need to upgrade to the latest version.
If you have a full node in your stack (running a website or other service) you need to upgrade that full node.
If you are using a full node as your wallet, good on you, you must be expert enough to not be surprised by anything in the post ;-)
This was a bit surprising, so this warrants a separate section.
The Bitcoin-ABC team has chosen to alter their client so miners running their software have to pay the ABC company 8% of the income made with this software. It is not unheard of for companies to start charging for their services, but as this is open source software AND there are several other competing products that do the same or better, it is extremely likely that miners will say no to the proposal and they will stop running the crippled software from the company shipping ABC.
After November 15th the ABC software will stubbornly refuse to follow the Bitcoin Cash chain as a result of this.
This means that people running the ABC client will have to migrate to a client that will actually rollow the Bitcoin Cash (BCH) chain. Check the BCH website for more: