epsilon <- c(0,rnorm(100))
S <- c(20,rep(0,100))
DS <- rep(0,101)

for(i in(1:100)) {
          
         DS[i+1] <- 0.0014*S[i] + 0.02*S[i]*epsilon[i+1] 

         S[i+1] = S[i] + DS[i+1]
              }

x <- seq(0,100)
xx <- as.data.frame(cbind(x, epsilon, DS, S))

plot(x, S, type="l", xlab="Periods", ylab="Stock price")

points(x,S)