short term capital gain

I m salaried person,

if I invest ₹10,000/- in stock, after 30-40 days I booked profit of ₹1500.

and with this profit+principal amount i.e. 11500/- reinvested in another stock (without withdrawal amount from demat account)

is me liable for short term capital gain

my thinking - a profit amount is not withdrawal from demat, so this gain is not enjoyed by me. only i switched the scheme of investment.

please correct if I m wrong