Stacking reward?  We aren't POS so if I understand your question there isn't a stacking reward.

To keep the rewards fair the block reward split is 45% miners/45% masternodes/10% decentralized governance.

Looks like the ROI is about 27% right now, which obviously doesn't include price growth.  You can check in depth real time stats here: https://masternode.terracoin.io/stats.php

Our goal is to be long term, stable and guided by decentralized governance, not just a quick buck flash in the pan coin.

You should check out the white paper and the weekly update with The Terracoin Foundations vision.

https://medium.com/@clockuniverse/terracoin-white-paper-ad4da0e75ba

https://medium.com/@clockuniverse/dec-28th-terracoin-update-vision-f053228dfbbb

Thanks for stopping by and welcome!