Frequently Asked Questions

What is Blocksale?

BLOCKSALE is an Ethereum based decentralized smart contract. BLOCKSALE is the first Ethereum DEX allowing staking of your desired coin, supporting limit and market orders, gas-free cancels, and the ability to earn from other people using the exchange.

How does BLOCKSALE work?

The smart contract is responsible for trust less storing of all assets and executing trade settlement, and all trades must be authorized by the user’s private keys.

The BLOCKSALE smart contract in beta will be a true DEX. Once we go live we will be implementing the hybrid dex model. This will enable BLOCKSALE to control the order in which transactions are processed, separating the act of trading from final settlement. When users trade their exchange balances will be updated in real-time, while simultaneously their private keys will be used to authorize the trade in the contract. This authorization prevents users from revoking any completed trades, and prevents BLOCKSALE from initiating any unauthorized trades.

Authorized transactions will be passed to the arbiter which manages the queue of pending transactions, dispatching them in sequence to ensure that each trade is mined in the correct order and that the smart contract balances stay in synch with the exchange balances. By controlling the transaction sequence, BLOCKSALE provides the speed and user experience of centralized exchanges combined with the security and auditability of decentralized exchanges.

How does the trading experience on BLOCKSALE compare to other Ethereum based decentralized exchanges?

The BLOCKSALE UX will match that of centralized exchanges while maintaining the security standards only available to decentralized exchanges. At this time our exchange operates solely as a DEX during beta.

What are the fees to trade on BLOCKSALE?

BLOCKSALE charges 0.2% for the market taker and 0.1% for the market maker. Users also pay gas fees to put their transactions on blockchain (read more below).

What is a maker and taker?

Market makers place new orders on the books and wait for another user to match them. They can be buys or sells. Market takers find existing orders on the books and fill them, thus taking orders off of the books.

I made a trade as a market taker, why was I charged more than 0.2%?

Market takers are responsible for covering the gas fees associated with each trade. Given our design, the exchange must pay this gas fee, priced in ether, when dispatching the trade to the network and then deduct it from the balance of the market taker. When exchanging tokens for ether the amount of eth deducted matches that of the gas fee. When exchanging ether for tokens, BLOCKSALE deducts the equivalent amount of tokens based on the price of the asset in ETH. This price is calculated using the average of the last 10 trades.

Ethereum gas prices have been increasing and often this fee is higher than the BLOCKSALE exchange fee of 0.2%. These high gas prices have led us to instituting order minimums in an attempt to reduce costs for our users (see question below on trade minimums).

What are gas fees?

All transactions on the Ethereum network cost gas, a fee that is paid to miners in order to process the transaction. Trades on BLOCKSALE cost ~140k gas. Gas costs are about 1.5x higher than EtherDelta and slightly higher than 0x, but on BLOCKSALE there is no risk of competing for the same order and wasting this gas fee. Traders receive their chosen order regardless of how long the transaction takes to settle, so as the exchange grows BLOCKSALE can continue to use a normal gas price.

Who pays the gas fees?

Users are responsible for covering all gas fees required to use the exchange. Deposit gas fees are paid directly by the user. On all other transactions and withdrawals, BLOCKSALE pays the gas fee to the network and deducts this fee from the user’s transaction. This includes both gas fees for trades, paid for by the taker, and gas fees for withdrawals, paid for by the customer. For trades and withdrawals the fee is taken out of the asset being traded/withdrawn. When withdrawing tokens the fee amount is calculated using the Token/ETH exchange rate from the last 10 trades.

Why can't I adjust the gas price for trades?

Because BLOCKSALE trades in real time and then mines the transactions afterwards, it is possible for trades to be dependent on other trades mining first. This means that one trade going slow could hold up many other trades and cause the exchange to essentially break. Therefore we set the gas price to ensure trades are able to mine in a reasonable amount of time.

Why are there minimum trade orders on BLOCKSALE?

BLOCKSALE has instituted a minimum order of 0.15 ETH (equivalent) for makers, and 0.05 ETH (equivalent) for takers.

Why is there a 0.04 ETH minimum withdrawal amount for all tokens?

Due to gas fees and how gas costs are applied to withdraws there is a 0.04 ETH minimum withdrawal for any given token. If you have less than 0.04 ETH deposited for a given token, please deposit more until you have at least 0.04 ETH equivalent and then withdraw the full amount.

Why won't my wallet balances update on the "Balances" page?

Due to node limitations, we only update wallet balances when the user queries them. On the balances page, you must first query Ethereum to find out your balance in your wallet (not the amount deposited to BLOCKSALE). You can update all balances at one with "Query all" or you can update each asset on its own with the "Query" button.

How much gas is needed to perform a trade?

Each trade costs ~140k gas. Traders will receive their chosen order regardless of how long the transaction takes to settle, so as the exchange grows they can continue to use a normal gas price.

Are my funds safe on BLOCKSALE?

Yes. All funds held within the BLOCKSALE wallet are under the user’s control at all times. BLOCKSALE can not trade, withdraw, or make any other transactions with your funds without you first cryptographically signing permission for BLOCKSALE to do so. Because BLOCKSALE keys are the only ones authorized to submit withdrawal transactions, we’ve included an escape hatch that allows users to withdraw directly from the contract after a certain period of inactivity. This ensures that even if the BLOCKSALE servers are unavailable that users can still remove their funds from the contract.

How do you safeguard my private key?

When a user unlocks their wallet, their private key is stored encrypted in browser memory and cannot be accessed outside of the BLOCKSALE app. Private keys are only accessed locally to sign transactions on behalf of a user and are never transmitted outside the device. On sign out, the private key is destroyed from memory and cannot be accessed.