diff --git a/README.md b/README.md
index 6ea24b1..cd4990b 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 [![Build Status](https://github.com/femtotrader/OnlinePortfolioAnalytics.jl/actions/workflows/CI.yml/badge.svg?branch=main)](https://github.com/femtotrader/OnlinePortfolioAnalytics.jl/actions/workflows/CI.yml?query=branch%3Amain)
 
-This project implements aims to provide users with functionality for performing quantitative portfolio analytics via [online algorithms](https://en.wikipedia.org/wiki/Online_algorithm).
+This project aims to provide users with functionality for performing quantitative portfolio analytics via [online algorithms](https://en.wikipedia.org/wiki/Online_algorithm).
 
 It depends especially on [OnlineStatsBase.jl](https://joshday.github.io/OnlineStats.jl/)
 
diff --git a/src/cumulative_return.jl b/src/cumulative_return.jl
index 1b56c24..da6881d 100644
--- a/src/cumulative_return.jl
+++ b/src/cumulative_return.jl
@@ -2,17 +2,17 @@ mutable struct CumulativeReturn{T} <: PortfolioAnalytics{T}
     value::T
     n::Int
 
-    sum::Sum
+    prod::Prod
 
     function CumulativeReturn{T}() where {T}
         val = zero(T)
-        s = Sum()
-        new{T}(val, 0, s)
+        p = Prod()
+        new{T}(val, 0, p)
     end
 end
 
 function OnlineStatsBase._fit!(stat::CumulativeReturn, data)
-    fit!(stat.sum, data)
+    fit!(stat.prod, 1 + data)
     stat.n += 1
-    stat.value = 1 + value(stat.sum)
+    stat.value = value(stat.prod)
 end
diff --git a/test/runtests.jl b/test/runtests.jl
index a61137f..32dcb63 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -214,8 +214,6 @@ const weights = [0.4, 0.4, 0.2]
             push!(cum_returns, value)
         end
         subscribe!(mapped_source, observer)
-        #@test isapprox(values[1], 1.1245, atol = ATOL)
-        #@test isapprox(values[end], 1.51812, atol = ATOL)
 
         expected_cum_returns = [
             1.1245,
@@ -231,7 +229,7 @@ const weights = [0.4, 0.4, 0.2]
             1.6222,
             1.4976
         ]
-        #println(cum_returns)
+        @test all(isapprox.(cum_returns, expected_cum_returns, atol = ATOL))
 
     end