Using structure matlab code - matlab

Question

I have recently been working in Matlab, so there are questions. Look at the code, please. If amountOfOptions = 2, I should get OptionPrice = [x x] . Vector Size OptionPrice(1x2). It seems he receives the output it produces but it gives the last result of the assignment.
function [startStockPrice, strike, barrier, riskFreeRate, timeToExpiry, volatility, CallOrPut, UpOrDown, OptionPrice, time] = OutBarrierOption(amountOfOptions)
%%%%%%%%%% Option parameters %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
startStockPrice = 70 + 40 * rand(1,amountOfOptions); % Stock price starts at $100.
strike = 120 + 30 * rand(1,amountOfOptions); % Strike price for the option ($).
barrier = 300 + 300 * rand(1,amountOfOptions); % Barrier price for the option ($).
riskFreeRate = 0.05 + 0.1 * rand(1,amountOfOptions); % 0.5 annual percent.
timeToExpiry = fix(1 + 3 * rand(1, amountOfOptions)); % Lifetime of the option in years. (Time to maturity)
volatility = 0.35 + 0.3 * rand(1,amountOfOptions); % 20% annual volatility. % UpOrDown - 'U' or 'D'
M = 1e4; % Number of Monte-Carlo trials
N = 100; % Number of observations
OptionPrice = 0;
tic;
for k = 1:amountOfOptions
dt(k)=timeToExpiry(k)/N;
for i=1:M
S(1) = startStockPrice(k)*exp((riskFreeRate(k)-(volatility(k)*volatility(k)/2)*dt(k)) + volatility(k)*sqrt(dt(k))*randn);
final_vals=[S(1)];
for j=1:N-1;
S(j + 1) = S(j)* exp((riskFreeRate(k) - 0.5* volatility(k)*volatility(k))*dt(k) + volatility(k)* sqrt(dt(k))* randn);
final_vals=S(1:j+1);
end
end
if max(final_vals) <= barrier(k)
option_values=max(final_vals - strike(k),0); % Evaluate the Call option options
present_vals = exp(-riskFreeRate(k)*timeToExpiry(k))*option_values; % Discount under r-n assumption
OptionPrice = mean(present_vals); % Take the average
else
% Hit the barrier, so the option is withdrawn.
present_vals = 0;
OptionPrice = mean(present_vals);
end
end
time = toc;
end