diff --git a/app/controllers/admin/students_controller.rb b/app/controllers/admin/students_controller.rb
index 6d6caa9..42c3d28 100644
--- a/app/controllers/admin/students_controller.rb
+++ b/app/controllers/admin/students_controller.rb
@@ -2,11 +2,12 @@ module Admin
   class StudentsController < Admin::ApplicationController
     # Overwrite any of the RESTful controller actions to implement custom behavior
     # For example, you may want to send an email after a foo is updated.
-    #
-    # def update
-    #   super
-    #   send_foo_updated_email(requested_resource)
-    # end
+
+    def update
+      super
+
+      create_portfolio_transaction!
+    end
 
     # Override this method to specify custom lookup behavior.
     # This will be used to set the resource for the `show`, `edit`, and `update`
@@ -42,5 +43,17 @@ class StudentsController < Admin::ApplicationController
 
     # See https://administrate-demo.herokuapp.com/customizing_controller_actions
     # for more information
+    #
+    private
+
+    def create_portfolio_transaction!
+      return unless fund_amount
+
+      PortfolioTransaction.create!(portfolio: requested_resource.portfolio, amount: fund_amount) if fund_amount
+    end
+
+    def fund_amount
+      @fund_amount ||= params['student']['add_fund_amount']
+    end
   end
 end
diff --git a/app/dashboards/portfolio_transaction_dashboard.rb b/app/dashboards/portfolio_transaction_dashboard.rb
index 0f943da..8d67f86 100644
--- a/app/dashboards/portfolio_transaction_dashboard.rb
+++ b/app/dashboards/portfolio_transaction_dashboard.rb
@@ -1,4 +1,4 @@
-require "administrate/base_dashboard"
+require 'administrate/base_dashboard'
 
 class PortfolioTransactionDashboard < Administrate::BaseDashboard
   # ATTRIBUTE_TYPES
@@ -9,11 +9,13 @@ class PortfolioTransactionDashboard < Administrate::BaseDashboard
   # on pages throughout the dashboard.
   ATTRIBUTE_TYPES = {
     id: Field::Number,
-    actor: Field::BelongsTo,
     portfolio: Field::BelongsTo,
-    transaction_type: Field::Select.with_options(searchable: false, collection: ->(field) { field.resource.class.send(field.attribute.to_s.pluralize).keys }),
+    transaction_type: Field::Select.with_options(searchable: false, collection: lambda { |field|
+                                                                                  field.resource.class.send(field.attribute.to_s.pluralize).keys
+                                                                                }),
+    amount: Field::Number.with_options(decimals: 2),
     created_at: Field::DateTime,
-    updated_at: Field::DateTime,
+    updated_at: Field::DateTime
   }.freeze
 
   # COLLECTION_ATTRIBUTES
@@ -23,7 +25,6 @@ class PortfolioTransactionDashboard < Administrate::BaseDashboard
   # Feel free to add, remove, or rearrange items.
   COLLECTION_ATTRIBUTES = %i[
     id
-    actor
     portfolio
     transaction_type
   ].freeze
@@ -32,7 +33,6 @@ class PortfolioTransactionDashboard < Administrate::BaseDashboard
   # an array of attributes that will be displayed on the model's show page.
   SHOW_PAGE_ATTRIBUTES = %i[
     id
-    actor
     portfolio
     transaction_type
     created_at
@@ -43,9 +43,9 @@ class PortfolioTransactionDashboard < Administrate::BaseDashboard
   # an array of attributes that will be displayed
   # on the model's form (`new` and `edit`) pages.
   FORM_ATTRIBUTES = %i[
-    actor
     portfolio
     transaction_type
+    amount
   ].freeze
 
   # COLLECTION_FILTERS
diff --git a/app/models/portfolio.rb b/app/models/portfolio.rb
index da52130..198a859 100644
--- a/app/models/portfolio.rb
+++ b/app/models/portfolio.rb
@@ -3,6 +3,10 @@ class Portfolio < ApplicationRecord
   has_many :portfolio_transactions
   has_many :portfolio_stocks
 
+  def cash_balance
+    portfolio_transactions.sum(:amount)
+  end
+
   # a User (specifically student) can buy a certain amount of stock
   def buy_stock(ticker, shares)
     stock = Stock.find_by(ticker:)
diff --git a/app/models/student.rb b/app/models/student.rb
index 71dfb88..43e6df0 100644
--- a/app/models/student.rb
+++ b/app/models/student.rb
@@ -1,4 +1,2 @@
 class Student < User
-    belongs_to :classroom
-    has_one :portfolio, foreign_key: 'user_id'
-end
\ No newline at end of file
+end
diff --git a/app/models/user.rb b/app/models/user.rb
index 16a0cc1..0afdf52 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,6 +1,7 @@
 class User < ApplicationRecord
   has_one :portfolio
   has_many :orders
+  belongs_to :classroom
 
   # Include default devise modules. Others available are:
   # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
diff --git a/app/views/admin/students/_form.html.erb b/app/views/admin/students/_form.html.erb
new file mode 100644
index 0000000..25fb1d1
--- /dev/null
+++ b/app/views/admin/students/_form.html.erb
@@ -0,0 +1,74 @@
+<%#
+# Form Partial
+
+This partial is rendered on a resource's `new` and `edit` pages,
+and renders all form fields for a resource's editable attributes.
+
+## Local variables:
+
+- `page`:
+  An instance of [Administrate::Page::Form][1].
+  Contains helper methods to display a form,
+  and knows which attributes should be displayed in the resource's form.
+
+[1]: http://www.rubydoc.info/gems/administrate/Administrate/Page/Form
+%>
+
+<%= form_for([namespace, page.resource], html: { class: "form" }) do |f| %>
+  <% if page.resource.errors.any? %>
+    <div id="error_explanation">
+      <h2>
+        <%= t(
+          "administrate.form.errors",
+          pluralized_errors: pluralize(page.resource.errors.count, t("administrate.form.error")),
+          resource_name: display_resource_name(page.resource_name, singular: true)
+        ) %>
+      </h2>
+
+      <ul>
+        <% page.resource.errors.full_messages.each do |message| %>
+          <li class="flash-error"><%= message %></li>
+        <% end %>
+      </ul>
+    </div>
+  <% end %>
+
+  <% page.attributes(controller.action_name).each do |title, attributes| -%>
+    <fieldset class="<%= "field-unit--nested" if title.present? %>">
+      <% if title.present? %>
+        <legend><%= t "helpers.label.#{f.object_name}.#{title}", default: title %></legend>
+      <% end %>
+
+      <% attributes.each do |attribute| %>
+        <div class="field-unit field-unit--<%= attribute.html_class %> field-unit--<%= requireness(attribute) %>">
+          <%= render_field attribute, f: f %>
+
+          <% hint_key = "administrate.field_hints.#{page.resource_name}.#{attribute.name}" %>
+          <% if I18n.exists?(hint_key) -%>
+            <div class="field-unit__hint">
+              <%= I18n.t(hint_key) %>
+            </div>
+          <% end -%>
+        </div>
+      <% end %>
+    </fieldset>
+    <% if action_name == 'edit' %>
+      <div class="field-unit">
+        <div class="field-unit__label"><label>Cash balance</label></div>
+        <div class="field-unit__field">
+          <%= sprintf('%.2f', page.resource&.portfolio&.cash_balance || 0)%>
+        </div>
+      </div>
+      <div class="field-unit">
+        <div class="field-unit__label"><label>Add funds</label></div>
+        <div class="field-unit__field">
+          <input step="any" type="number" name="student[add_fund_amount]" id="student_add_fund_amount">
+        </div>
+      </div>
+    <% end %>
+  <% end -%>
+
+  <div class="form-actions">
+    <%= f.submit %>
+  </div>
+<% end %>
diff --git a/config/environments/test.rb b/config/environments/test.rb
index adbb4a6..b8825b2 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -61,4 +61,7 @@
 
   # Raise error when a before_action's only/except options reference missing actions
   config.action_controller.raise_on_missing_callback_actions = true
+
+  # TODO: revisit
+  config.assets.css_compressor = nil
 end
diff --git a/config/routes.rb b/config/routes.rb
index 577bea4..a836d68 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -7,7 +7,7 @@
 
     # resources :portfolios
     # resources :portfolio_stocks
-    # resources :portfolio_transactions
+    resources :portfolio_transactions, except: [:index]
     resources :students
     resources :teachers
     resources :users
diff --git a/db/migrate/20240531145714_add_amount_to_portfolio_transactions.rb b/db/migrate/20240531145714_add_amount_to_portfolio_transactions.rb
new file mode 100644
index 0000000..508d88d
--- /dev/null
+++ b/db/migrate/20240531145714_add_amount_to_portfolio_transactions.rb
@@ -0,0 +1,5 @@
+class AddAmountToPortfolioTransactions < ActiveRecord::Migration[7.1]
+  def change
+    add_column :portfolio_transactions, :amount, :decimal, precision: 8, scale: 2, null: false
+  end
+end
diff --git a/db/migrate/20240531151002_remove_cash_balance_from_portfolios.rb b/db/migrate/20240531151002_remove_cash_balance_from_portfolios.rb
new file mode 100644
index 0000000..67cffd3
--- /dev/null
+++ b/db/migrate/20240531151002_remove_cash_balance_from_portfolios.rb
@@ -0,0 +1,5 @@
+class RemoveCashBalanceFromPortfolios < ActiveRecord::Migration[7.1]
+  def change
+    remove_column :portfolios, :cash_balance
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index b3274e4..8b3f071 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -53,12 +53,12 @@
     t.integer "transaction_type"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.decimal "amount", precision: 8, scale: 2, null: false
     t.index ["portfolio_id"], name: "index_portfolio_transactions_on_portfolio_id"
   end
 
   create_table "portfolios", force: :cascade do |t|
     t.bigint "user_id", null: false
-    t.float "cash_balance"
     t.float "current_position"
     t.json "transactions"
     t.datetime "created_at", null: false
diff --git a/test/controllers/admin/students_controller_test.rb b/test/controllers/admin/students_controller_test.rb
new file mode 100644
index 0000000..759283f
--- /dev/null
+++ b/test/controllers/admin/students_controller_test.rb
@@ -0,0 +1,29 @@
+require 'test_helper'
+
+class Admin::StudentsControllerTest < ActionDispatch::IntegrationTest
+  setup do
+    @student = users(:one)
+  end
+
+  test 'should update student email' do
+    @student.update_attribute(:email, 'nottest@nottest.com')
+
+    patch admin_student_url(@student), params: { student: { email: 'test@test.com' } }
+    @student.reload
+    assert_equal 'test@test.com', @student.email
+    assert_redirected_to admin_student_url(@student)
+  end
+
+  test 'given a add_fund_amount, creates a transaction' do
+    assert_difference('PortfolioTransaction.count', 1) do
+      patch admin_student_url(@student), params: { student: { add_fund_amount: '10.50' } }
+    end
+
+    transaction = PortfolioTransaction.last
+
+    assert_equal 10.50, transaction.amount
+    assert_equal @student.reload.portfolio.portfolio_transactions.last, transaction
+
+    assert_redirected_to admin_student_url(@student)
+  end
+end
diff --git a/test/fixtures/portfolio_transactions.yml b/test/fixtures/portfolio_transactions.yml
index 8e51926..8dc242f 100644
--- a/test/fixtures/portfolio_transactions.yml
+++ b/test/fixtures/portfolio_transactions.yml
@@ -2,8 +2,10 @@
 
 one:
   portfolio: one
+  amount: 10.00
   transaction_type: 1
 
 two:
-  portfolio: two
+  portfolio: one
+  amount: 15.50
   transaction_type: 1
diff --git a/test/fixtures/portfolios.yml b/test/fixtures/portfolios.yml
index 156f883..f1c9c49 100644
--- a/test/fixtures/portfolios.yml
+++ b/test/fixtures/portfolios.yml
@@ -2,12 +2,10 @@
 
 one:
   user: one
-  cash_balance: 1.5
   current_position: 1.5
-  transactions: 
+  transactions:
 
 two:
   user: two
-  cash_balance: 1.5
   current_position: 1.5
-  transactions: 
+  transactions:
diff --git a/test/fixtures/users.yml b/test/fixtures/users.yml
index 82fa2a2..dc3b46e 100644
--- a/test/fixtures/users.yml
+++ b/test/fixtures/users.yml
@@ -4,10 +4,12 @@
 # model remove the "{}" from the fixture names and add the columns immediately
 # below each fixture, per the syntax in the comments below
 #
-one: 
-  username: "lkfjd"
+one:
+  username: abc123
+  classroom: one
 # column: value
 #
 two:
-  username: "dglk"
+  username: def123
+  classroom: two
 # column: value
diff --git a/test/fixtures/years.yml b/test/fixtures/years.yml
index 338db83..e066652 100644
--- a/test/fixtures/years.yml
+++ b/test/fixtures/years.yml
@@ -1,7 +1,7 @@
 # Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
 
 one:
-  year: 1
+  year: 2023
 
 two:
-  year: 2
+  year: 2024
diff --git a/test/models/portfolio_test.rb b/test/models/portfolio_test.rb
index 1c329a7..692d1f2 100644
--- a/test/models/portfolio_test.rb
+++ b/test/models/portfolio_test.rb
@@ -1,8 +1,9 @@
-require "test_helper"
+require 'test_helper'
 
 class PortfolioTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
-  #TODO: Add tests for the Portfolio model
+  fixtures :portfolios
+  test '#cash_balance' do
+    portfolio = portfolios(:one)
+    assert_equal BigDecimal('25.50'), portfolio.cash_balance
+  end
 end