Staking FAQs Answered

Disclaimer: I am not a member of the Polkadot or W3F team so please take all information below with a grain of salt. I have done my best to provide accurate information but anything seen here should be validated independently. The Polkadot wiki is a great place to cross-reference with and actually covers most of what I will be explaining.

It seems every other post these days is in some way related to issues with staking, questions about receiving rewards, how to check the minimum nomination requirement, etc. This is a brief guide intended to answer common questions and consolidate information that I have personally researched in order to help others. If anything appears to be incorrect, please let me know. I can also update with other information if anyone has requests.

Intro/How Staking on Polkadot Works

Polkadot uses Nominated Proof-of-Stake (NPoS) for validating blocks and achieving consensus. I won't go into too much detail on this, but for Polkadot the staking process involves bonding some amount of your DOT and nominating validators that will help to verify the shared state of the blockchain as well as produce blocks.

I also won't go into how to get set up to start staking as there are plenty of existing guides (using polkadot.js, Ledger Live, or on a CEX for example). Just note that the questions answered below are relevant to staking directly on chain.

Staking FAQs

• What is the minimum amount of DOT required to stake?
  • Technically, the minimum amount of DOT required to stake is 10. However, you WILL NOT earn any rewards nominating with this amount as of now. Nomination pools are currently being tested on Kusama and should make there way to Polkadot in the future. This should help a lot of users with lower amounts to stake to be able to earn rewards. More info. here.
• What is the minimum amount of DOT required to stake and earn rewards?
  • This amount is dynamic and can change each era. As of the time of this post, the amount is 154.411 DOT. Again, there is a caveat to this number. It really means that there is at least one nominator that is earning rewards when nominating with this amount of DOT. The reality is that many over-subscribed validators will require you to have much more DOT than this to be one of the top 256 nominators selected. For example, this validator hit the cutoff at 446 DOT and any nominator subscribed with less than that will not receive rewards this era (found on the Staking Overview page in polkadot.js):

Over-subscribed cutoff.

• The current min nominated amount can be found at the top of the Targets page on polkadot.js:

Min Nominated Amount

• What is the minimum amount of DOT required to stake and reliably earn rewards?
  • This is harder to say, as it would depend on the validators that you've selected to nominate and whether or not they become over-subscribed in any given era, along with the amount of DOT that the top 256 nominators have bonded. Your best bet is to try to choose validators that don't become over-subscribed, but of course this can never be assured as they may change over time as more people nominate them. You could also look at the cut-off amounts for several validators that are over-subscribed to get an idea of what a reliable amount would be. Somewhere around 250-300 DOT would certainly give you a better chance if you are nominating some of the more popular validators. The highest cutoff I saw for an oversubscribed validator was about 600 DOT for this era.
• How long is the unbonding period (DOT is still locked during this period and rewards are no longer earned)?
  • 28 days
• How long before you start earning rewards?
  • When first nominating validators, your nominations will go into effect at the start of the next era (current era + 1). This is currently at about 3:36 pm UTC for Polkadot. Then, during that era (current era + 1) the validator you nominated does its thing and earns era points. Finally, the payouts are rewarded at the beginning of the next era (current era + 2). Note that someone will then have to pay a small fee to distribute the rewards to each nominator but usually the validator will do that as a courtesy. Because of this, there may be some delay between when rewards are awarded and when they are paid out to you.
• Can I add more DOT to my existing bonded stake?
  • Yes, under Staking -> Accounts on Polkadot.js, click on the 3 dots next to your account. Choose the option "Bond more funds".
• Can I change my selected validators while currently staking?
  • Yes, but you will need to pay a small fee to update them. The validators should switch when the next era begins.
• How are validators and their respective nominators chosen each era?
  • I won't pretend to understand the algorithm completely, but you can read up on the process here: NPoS Election Algorithms. One thing to note is that the nominator/validator solution is computed off-chain to avoid altering the 6 second block time, otherwise the computation would slow down block production time at the end of an era. This leads to several functions that are not permitted during the last quarter of the session before an era change, such as bondExtra, unbond, nominate, and others. A session is listed as a 4 hour time period so that means the last hour in an era will not allow these actions.
• Are there any ways of improving my chances of earning rewards when just above the minimum nominated amount?
  • Yes, there was functionality added on Polkadot called a bags-list. This is essentially an ordered list of nominators grouped by the amount bonded. Nominators within a particular bag are not necessarily ordered by the amount bonded, however, and you may need to reposition yourself within the bag to potentially move ahead of others that are staking less than you are. It still may not guarantee that you start getting rewards but it could improve your chances. See this article for details and the process on polkadot.js.

If you have any questions feel free to ask and I'll do my best to answer. I will also update the guide if there is more important information that is brought up or if something is incorrect or unclear.

Thanks for reading and happy staking!