Why not simply have two tables - your user and a simpler movements table

Movements would be something like:

user_id
movement_type  (1, incoming, 2 outgoing)
movement_amount
movement_date

You can then do everything

maybe you need to have a 'transactions' table?

1. id - the transaction id
2. timestamp - when did this transaction occurred (im not sure why you are hardcoding days 1-7)
3. user_id - to which user this transaction is for
4. incoming - deposits/debits
5. outgoing - withdrawal/credit
6. balance - running balance

sample entry would be

id	timestamp	user_id	incoming	outgoing	balance
1	2017-07-01	1	20	        0	        20
2	2017-07-02	1	0	        100	        120

and so on

so, you could access the 5th day transaction's balance for example as

$balance = $user->transactions()->get(4)->balance