plotting multiple brownian motions curves on the same plot

I have the following code to create the random path of a geometic brownian motion but I want to plot every iteration on top of eachother to look like the following

https://www.reddit.com/r/dataisbeautiful/comments/7omtm5/a_plot_of_10000_random_walkers_utilizing_brownian/ .

I have read all online sources from matlab and watch youtube videos to try and help but nothing I do works.

%Generates the path of the underlying for a monte carlo simulated stock
%http://ac.aua.am/tigran_bunarjyan/Public/NA_Monte%20Carlo%20Presentation.pdf

clear all
clc

S=100;
sigma=0.3;
T=1;
r=0.05;

step=1000;
dt=T/step;
sqdt=sqrt(dt);

rr=randn(1, step);

St=S;

stockPrices=[];
ts=[];

stockPrices(1)=S;
ts(1)=0;


for st=1:step
    St=St*(1+r*dt+sigma*sqdt*rr(1,st));
    stockPrices(st+1)=St; 
    ts(st+1)=st;  
end


plot(ts,stockPrices)
title("Stock Price for Day =0...500");
xlabel=("Day");
ylabel=("Price");

[Jan]

Katie Brewer has removed the contents of all of her questions. It seems, like she is not interested in a cooperative usage of the forum. What a pity.

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Naman Bhaia]

Hey Katie,

According to my understanding you are generating only one plot. If you want to plot a graph for each iteration of the for loop do the following

1. 1. Place the “plot” command inside the for loop
2. 2. Before the for loop use “hold on” command
3. 3. After the for loop use the “hold off” command

For more clarification on hold command you can refer to this link.

Consider the following example

hold on
for i=1:101
    j=i;
    plot(i,j,'x');
end
hold off