compound-interest Neo Bank VS SSF

compound-interest.rb

# only runnable inside Rails web application
include ActionView::Helpers::NumberHelper

def to_idr(amount)
  number_to_currency(amount, unit: 'Rp.', precision: 3)
end

def noebank
  net_worth = 0
  emergency_fund = 30_000_000
  monthly_deposit = 12_000_000
  net_worth += emergency_fund
  deposit_date = 28
  interest_rate = 0.06
  tax_percentage = 0.2
  start_date = Date.new(2020, 1, 1)
  end_date = Date.new(2020, 12, 31)
  (start_date).upto(end_date).each do |date|
    net_worth += monthly_deposit if date.day == deposit_date
    daily_fee = net_worth * interest_rate * 1.0 / 365
    tax = daily_fee * tax_percentage
    income = daily_fee - tax
    net_worth += income
  end
  puts '===Neo Bank==='
  puts "Monthly Deposit\t: #{to_idr(monthly_deposit)}"
  puts "Fee p.a\t\t: 6%"
  puts "Tax\t\t: 20% per disburse"
  puts "Emergency Fund\t: #{to_idr(emergency_fund)}"
  puts "Total net worth\t: #{to_idr(net_worth)}"
end

def ssf_in_one_year
  monthly_deposit = 12_000_000
  emergency_fund = 30_000_000
  investment_worth = 148_498_364 # taken from bibit: https://app.bibit.id/reksadana/RD3561
  puts '===Sukorinvest Stable Fund (SSF)==='
  puts "Monthly Deposit\t: #{to_idr(monthly_deposit)}"
  puts "Fee p.a\t\t: 6,89%"
  puts "Tax\t\t: None"
  puts "Emergency Fund\t: #{to_idr(emergency_fund)}"
  puts "Total net worth\t: #{to_idr(emergency_fund + investment_worth)}"
end

noebank
puts "\n"
ssf_in_one_year

# Example Result:
# 
# ===Neo Bank===
# Monthly Deposit : Rp.12,000,000.000
# Fee p.a         : 6%
# Tax             : 20% per fee disburse
# Emergency Fund  : Rp.30,000,000.000
# Total net worth : Rp.178,780,869.597

# ===Sukorinvest Stable Fund (SSF)===
# Monthly Deposit : Rp.12,000,000.000
# Fee p.a         : 6,89%
# Tax             : None
# Emergency Fund  : Rp.30,000,000.000
# Total net worth : Rp.178,498,364.000