You can check the historical data on CoinMarketCap:
Steem (STEEM) Historical Data | CoinMarketCap.

For example:
Yesterday (2018.10.26) the closing price for the Steem was $0.793405 USD.
2 days ago (on 2018.10.25) the closing price for the Steem was 0.800649 USD.

Image source: https://images-na.ssl-images-amazon.com.

The rules of this contest

• Write the price that you think will be the closing price for the Steem for today (2018.10.27).
• Only one guess (prediction) per account.
• The author with the closest price will win the 100% of the Steem Dollars (SBD) rewards from this post.
• Upvoting and resteeming are not required, but helps the contest.
• If this contest will be successful, I will do more in the future.

The main goals of this contest

• Help plankton (redfish) and minnow users by giving them a chance to win Steem Dollars (SBD).
• Encourage engagement (commenting) on Steemit.

So feel free to talk about the price of the Steem and the price of the Steem Dollars (SBD) in the comments, but only the guesses for the closing price of the Steem will play in this contest.

Good luck with your prediction!
Have a nice day and have a nice weekend!