Important: Lot Size Change on XBTUSD Swap and Futures – Moving to 100 Contract Lot Size Effective 8 June

We are making it easier and more intuitive to trade on BitMEX by changing the Lot Size, or minimum trading unit, on our popular XBTUSD Swap and XBT futures (XBTM21 and XBTU21) from 1 contract to 100 contracts, effective 04:30 UTC on 8 June 2021.  

We ask that traders adjust their positions, strategies, and systems to account for this change – especially amending open positions and orders to reflect the new Lot Size.

We expect a pause in trading of 10 seconds starting at 04:30 UTC on 8 June 2021 to apply the Lot Size change.

Amending Lot Sizes will bring clear benefits for our users, including more responsive markets and better platform scaling with higher XBT prices. It also addresses a persistent issue with rounding, that affects the settlement value of small trades, and has created confusion for some users. More technical information is available in this post.

What Will Happen on 8 June 2021?
At 04:30 UTC on 8 June, we will round down existing positions to the nearest ‘round lot’ by closing out excess contracts (‘odd lots’)  at Mark Price. Here are two examples:

A position of 2,135 contracts on the affected products will become a position of 2,100 contracts after we close out the odd-lots (35 contracts) at Mark Price. There will be no fees charged for the trade. 

A position of 99 contracts on the affected products will be closed out at Mark Price (no fees) because it is smaller than the new Lot Size of 100. 

What Happens to Odd Lot Orders after the Change?

After the change, orders that are not in multiples of Lot Size (i.e. 100) will be rejected.

What Will Happen to Open Orders?

Open orders for contract sizes smaller than 100 will be canceled, while open orders for contracts greater than 100 will be automatically rounded down to the nearest Round Lot. Partially filled open orders will be cancelled / rounded down based on the unfilled quantity (leavesQty). If you have advanced order types – like Hidden orders – with an Odd Lot displayQty, they will also be canceled. 

What Do I Need to Do before 8 June 2021?

We are encouraging every user to check their positions on the XBTUSD Swap, XBTM21, and XBTU21 as soon as possible and to consider partially closing or increasing your positions to be in Round Lots (multiples of 100 contracts). Here are some examples:

Trader A has an open position of 75 contracts on the XBTUSD Swap. Before the deadline, they increase their position by 25 contracts, for a total of 100 contracts.

Trader B has an open position of 3,335 contracts on XBTM21. Before the deadline, they close 35 contracts for a total of 3,300 contracts.

Trader C has an open position of 50 contracts on XBTU21. They don’t make any changes to their position before the deadline, so at 04:30 UTC on 8 June 2021 their position is automatically closed out, without fee, at Mark Price.

Traders using API or 3rd party systems will also need to make changes to take the Lot Size setting into account for the instruments they are trading.

While overall this is a positive move in the long-term, we’re mindful this will affect many users, and will be reminding our community on social media and by direct email as the deadline approaches. 

The Bottom Line

Over the past few years, Bitcoin has appreciated in price and popularity, which is good news for everyone involved in the crypto ecosystem. Our Lot Size is now too small to make markets as responsive as our users have come to expect, so we are optimising the way the contract trades on our platform by increasing the Lot Size from 1 to 100. We’re confident that this change will benefit all BitMEX users, while setting the platform up for Bitcoin’s next act.