A broad round of trading and account improvements.

• Added an expiration-date selector with a calendar to the options order flow
• Standardized money and price formatting across the app, including more decimals on low-priced values
• Deposit and withdrawal screens now hide unsupported networks, preventing failed transfers
• Password reset now sends a branded email, and login gained rate limiting to better protect accounts
• The sign-up form pre-fills your email from your invite link and shows a loading state on submit