Prediction option put and call : I have to predict the purchase or not of the sp500 put and call options, however I do not understand some parts of the code that was provided to me. In addition can you explain to me what each option of the data does (example: option clothing price, option settle price , optiontype ,optionstrike, optionhighprice ,optionlowprice ,optionvol , optionopenint ) and their utility? We try to use Arima for the prediction but do you have any other solution to offer me? Thank you in advance and here is the piece of code that I do not understand:

    `  mutate(optiontype = as.double(optiontype == "put")) %>%
    mutate(buy_gain = (optionstrike - settle_sp_price)*(optiontype*2 - 1)) %>%
    mutate(bet_price = optionstrike - optionclosingprice*(optiontype*2 - 1))
    prices <- options %>% 
    select(todaydate, today_sp_price) %>%
    unique() %>%
    mutate(lag_one = lag(today_sp_price), lag_three = lag(today_sp_price, 3), 
    lag_five = lag(today_sp_price, 5) ) %>%
    select(-(today_sp_price)) `

What is bet price ? 
  

