When discussing options, it's important to understand the concept of being "in-the-money." A call option is considered deep-in-the-money when the strike price is significantly lower than the current price of the underlying instrument. Conversely, a put option is deep-in-the-money when the strike price is well above the current price of the underlying instrument. This indicates that the option has a high intrinsic value and can be exercised for a profit. So, in short, being deep-in-the-money means having a favorable position in the options market.