Get Stock Prices and Convert to Returns
Ra <- c("AAPL", "GOOG", "NFLX") |>
tq_get(get = "stock.prices",
from = "2010-01-01",
to = "2015-12-31") |>
group_by(symbol) |>
tq_transmute(select = adjusted,
mutate_fun = periodReturn,
period = "monthly",
col_rename = "Ra")
Ra
## # A tibble: 216 × 3
## # Groups: symbol [3]
## symbol date Ra
## <chr> <date> <dbl>
## 1 AAPL 2010-01-29 -0.103
## 2 AAPL 2010-02-26 0.0654
## 3 AAPL 2010-03-31 0.148
## 4 AAPL 2010-04-30 0.111
## 5 AAPL 2010-05-28 -0.0161
## 6 AAPL 2010-06-30 -0.0208
## 7 AAPL 2010-07-30 0.0227
## 8 AAPL 2010-08-31 -0.0550
## 9 AAPL 2010-09-30 0.167
## 10 AAPL 2010-10-29 0.0607
## # ℹ 206 more rows
Get Baseline and Convert to Returns
Rb <- "XLK" |>
tq_get(get = "stock.prices",
from = "2010-01-01",
to = "2015-12-31") |>
group_by(symbol) |>
tq_transmute(select = adjusted,
mutate_fun = periodReturn,
period = "monthly",
col_rename = "Rb")
Rb
## # A tibble: 72 × 3
## # Groups: symbol [1]
## symbol date Rb
## <chr> <date> <dbl>
## 1 XLK 2010-01-29 -0.0993
## 2 XLK 2010-02-26 0.0348
## 3 XLK 2010-03-31 0.0684
## 4 XLK 2010-04-30 0.0126
## 5 XLK 2010-05-28 -0.0748
## 6 XLK 2010-06-30 -0.0540
## 7 XLK 2010-07-30 0.0745
## 8 XLK 2010-08-31 -0.0561
## 9 XLK 2010-09-30 0.117
## 10 XLK 2010-10-29 0.0578
## # ℹ 62 more rows
Join the Two Tables
RaRb <- left_join(Ra, Rb, by = c("date" = "date"))
RaRb
## # A tibble: 216 × 5
## symbol.x date Ra symbol.y Rb
## <chr> <date> <dbl> <chr> <dbl>
## 1 AAPL 2010-01-29 -0.103 XLK -0.0993
## 2 AAPL 2010-02-26 0.0654 XLK 0.0348
## 3 AAPL 2010-03-31 0.148 XLK 0.0684
## 4 AAPL 2010-04-30 0.111 XLK 0.0126
## 5 AAPL 2010-05-28 -0.0161 XLK -0.0748
## 6 AAPL 2010-06-30 -0.0208 XLK -0.0540
## 7 AAPL 2010-07-30 0.0227 XLK 0.0745
## 8 AAPL 2010-08-31 -0.0550 XLK -0.0561
## 9 AAPL 2010-09-30 0.167 XLK 0.117
## 10 AAPL 2010-10-29 0.0607 XLK 0.0578
## # ℹ 206 more rows
Calculate CAPM
RaRb_capm <- RaRb |>
tq_performance(Ra = Ra,
Rb = Rb,
performance_fun = table.CAPM,
scale = 12)
RaRb_capm
## # A tibble: 1 × 17
## ActivePremium Alpha AlphaRobust AnnualizedAlpha Beta `Beta-` `Beta-Robust`
## <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 0.188 0.0216 0.0097 0.292 0.880 0.150 1.31
## # ℹ 10 more variables: `Beta+` <dbl>, `Beta+Robust` <dbl>, BetaRobust <dbl>,
## # Correlation <dbl>, `Correlationp-value` <dbl>, InformationRatio <dbl>,
## # `R-squared` <dbl>, `R-squaredRobust` <dbl>, TrackingError <dbl>,
## # TreynorRatio <dbl>