My Opinion.
Depends on how you define capitalism.....
"Islamic" systems are based on the principle of Tawheed.(One God)--what this has to do with economics you might wonder----from the principle of Tawheed flows two other principles, that of 1)Trusteeship (Khalifa) and 2)Equality.
What this means in socio-economic terms is that all wealth and the means to generate wealth is a blessing from God----a Trusteeship that comes with responsibility. Since all human beings are equal, irrespective of wealth, no one has the exclusive "right" to wealth-----everyone in the community/nation/globe has an equal right to achieve wealth. This means that any system that assigns special priviledges to wealthy individuals, corporations or nations, at the expense of those who have less, is an unjust system.
In such an economic system, taxes are to be used for those in society/community in need---in areas such as healthcare, education, welfare of the elderly, those in need...etc---this creates a flow of money in society. ---that is, rather than money stagnating in stock markets, banks, financial intitutions---money flows back into society to create better lives for everyone. Financing is a necessary tool to generate wealth---Financing must be based on equality----that is both the lender and the borrower have a partnership that shares the profits and risks of a venture. Thus---money used to generate money is an unjust concept that priviledges the lender over the borrower creating inequality. On the other hand ---financing used as a tool to generate profits through trade (goods,services) creates benefits to both lender and borrower and is better for society as a whole.---it creates a flow of money. Money that circulates in society creates benefits for everyone, money that stagnates in the hands of a few---who get richer and richer---is an unjust system that benefits only a few.
Another important concept of bussiness and economics mentioned in the Quran is transparency. This eliminates "crony capitalism" (a problem in the East) and lessens misunderstandings and disputes. It also provides for clear oversight and a counterbalance to unjust practices.
Money/wealth does not belong to any individual or nation---it belongs to God and we are his trustees. Because it belongs to God, everyone has a right to it---therefore, wealth must be shared........