Install Packages

# install.packages("quantmod")
library("quantmod")
## Loading required package: xts
## Loading required package: zoo
## 
## Attaching package: 'zoo'
## The following objects are masked from 'package:base':
## 
##     as.Date, as.Date.numeric
## Loading required package: TTR
## Registered S3 method overwritten by 'quantmod':
##   method            from
##   as.zoo.data.frame zoo

Question 5

Check if the following function description is correct:

#####In quantmod package, getSymbols() function loads and manage data from multiple sources such as yahoo finance, FRED, oanda, google, MySQL, csv, RData and Alpha Vantage.

methods(getSymbols)
## Warning in .S3methods(generic.function, class, envir, all.names = all.names, :
## function 'getSymbols' appears not to be S3 generic; found functions that look
## like S3 methods
##  [1] getSymbols.alphavantage getSymbols.av           getSymbols.csv         
##  [4] getSymbols.FRED         getSymbols.google       getSymbols.mysql       
##  [7] getSymbols.MySQL        getSymbols.oanda        getSymbols.rda         
## [10] getSymbols.RData        getSymbols.SQLite       getSymbols.tiingo      
## [13] getSymbols.yahoo        getSymbols.yahooj      
## see '?methods' for accessing help and source code

Question 6

Which code return(s) the daily stock prices for Microsoft during 2025-10-01 ~ 2026-01-31?

getSymbols("MSFT", src="yahoo", from = "2025-10-01", to = "2026-01-31")
## [1] "MSFT"

Question 7

How many days of stock prices did you obtain?

nrow(MSFT)
## [1] 84

Question 8

Which time period did Microsoft’s Open prices reach the highest?

open_prices <- MSFT$MSFT.Open
max(open_prices)
## [1] 550
index(open_prices)[which.max(open_prices)]
## [1] "2025-10-28"
plot(MSFT$MSFT.Open, main = "MSFT Open Prices")